Ah well, I was tempted to provide some alternate embarks in the spirit of competition, but after the first one ran into trouble getting multi-thousand edge pop towns with necro towers (got one or other). Looking forward to report!
(And, wow, I learned how used I am to alt-tabbing into dfhack and hitting up to kill df)
EDIT: Ah, what the hell. Posting anyway since I already have the post mostly completed, and while not perfect I think they're good enough to pay attention to be improved.
The list of things asked for is kind of short and I was bored (in retrospect, I got bored of this too...2000 year worldgens with 25k world pops take a while)
, so did few worldgens (though Gwolfski's is pretty good too, all told, competition is cool!):
Somthur, year 117:

Joyous tropical forest(should have unicorns according to populations, but didn't see them), Terryfing Tropical Savanna (no reanimation or evil rain, as dangerous as hill of death), gear-destroyingly cold glacier (I pastured a cat and they went missing after 2 months or so - a dwarven caravan passed over it and arrived to depot with x and X gear. Then promptly turned it into corpse stockpile), numerous sources of sand, including right on the left oceanshore for magma-safe components - and you'll want it, given my digging in mostly northern parts discovered no iron-bearing ores (gold, sphalerite, copper galena and such were present, though). If you desire no aquifer, the second ocean biome will let you through.
Sure, the embark is kind of large-tbh, can easily cut down the south row. However, being 1 cavern world, it is not that fat - highest z at 125, lowest at 76.
More interestingly, however, the world is on the precipice of a war. Come late 119, the major human town would be taken over by elves and go on to become thousands strong beast with constant conflicts causing waxing and waning of the size, while kobolds, proud in their cave, would take over two forest retreats themselves. An unexplored option is running Somthur for 2-300 years, and then make yourself stand steadfast against the thousands strong combined army of elves, goblins and humans issuing forth from the town.
A stone thrown into the pond will mess it up (Ran two years to see if No Trade actually results in no trade from 118 and humans went to war with dwarves before their first caravan and elves after their first caravan (I ignored it to keep things ~same)).
The war was very successful for humans and elves. Soon, the last two dwarven hillocks will fall, leaving you alone with them:

At embark time, the major town has in the vicinity of 860 sentients, the major forest retreat on world's edge has 700ish with over a thousand of giant animals (and few unicorn), the dark fortress has 10k goblins with 2,5k of beak dogs, trolls and ogres each. A plains titan, a roc and dragon are in the world as well (the demon panther lord of goblins hunts down dragons and bronze colossi for sport!).
On your side, there's a cave with 122 kobolds and dwarven halls with total combined of 850ish sentients.
Created in DF v0.43.05.
[WORLD_GEN]
[TITLE:SharpCracklife]
[SEED:Qwo22GSikmsqaWqGYQAE]
[HISTORY_SEED:kuaa6kyC8aIKcCCUIQIo]
[NAME_SEED:I0oecQkw0gwWQMwcskam]
[CREATURE_SEED:QewscE80QGeUMEykoYWe]
[DIM:17:17]
[EMBARK_POINTS:1503]
[END_YEAR:117]
[BEAST_END_YEAR:1000:-1]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:1]
[ELEVATION:99:330:0:0]
[RAINFALL:0:100:0:0]
[TEMPERATURE:-300:85:0:0]
[DRAINAGE:0:100:3200:3200]
[VOLCANISM:0:100:0:0]
[SAVAGERY:0:100:0:0]
[ELEVATION_FREQUENCY:1:1:1:1:1:1]
[RAIN_FREQUENCY:1:1:1:1:1:1]
[DRAINAGE_FREQUENCY:1:1:1:1:1:1]
[TEMPERATURE_FREQUENCY:1:1:1:1:1:1]
[SAVAGERY_FREQUENCY:1:1:1:1:1:1]
[VOLCANISM_FREQUENCY:1:1:1:1:1:1]
[POLE:SOUTH]
[MINERAL_SCARCITY:1000]
[MEGABEAST_CAP:8]
[SEMIMEGABEAST_CAP:15]
[TITAN_NUMBER:1]
[TITAN_ATTACK_TRIGGER:20:0:0]
[DEMON_NUMBER:15]
[NIGHT_TROLL_NUMBER:0]
[BOGEYMAN_NUMBER:0]
[VAMPIRE_NUMBER:20]
[WEREBEAST_NUMBER:20]
[SECRET_NUMBER:200]
[REGIONAL_INTERACTION_NUMBER:0]
[DISTURBANCE_INTERACTION_NUMBER:0]
[EVIL_CLOUD_NUMBER:15]
[EVIL_RAIN_NUMBER:0]
[GENERATE_DIVINE_MATERIALS:1]
[GOOD_SQ_COUNTS:4:0:0]
[EVIL_SQ_COUNTS:0:0:200]
[PEAK_NUMBER_MIN:0]
[PARTIAL_OCEAN_EDGE_MIN:0]
[COMPLETE_OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:0]
[REGION_COUNTS:SWAMP:0:0:0]
[REGION_COUNTS:DESERT:0:0:0]
[REGION_COUNTS:FOREST:0:0:0]
[REGION_COUNTS:MOUNTAINS:0:0:0]
[REGION_COUNTS:OCEAN:0:0:0]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:0:0:0]
[REGION_COUNTS:HILLS:0:0:0]
[EROSION_CYCLE_COUNT:20]
[RIVER_MINS:0:0]
[PERIODICALLY_ERODE_EXTREMES:0]
[OROGRAPHIC_PRECIPITATION:0]
[SUBREGION_MAX:5000]
[CAVERN_LAYER_COUNT:1]
[CAVERN_LAYER_OPENNESS_MIN:100]
[CAVERN_LAYER_OPENNESS_MAX:100]
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:0]
[CAVERN_LAYER_PASSAGE_DENSITY_MAX:0]
[CAVERN_LAYER_WATER_MIN:30]
[CAVERN_LAYER_WATER_MAX:40]
[HAVE_BOTTOM_LAYER_1:1]
[HAVE_BOTTOM_LAYER_2:1]
[LEVELS_ABOVE_GROUND:5]
[LEVELS_ABOVE_LAYER_1:5]
[LEVELS_ABOVE_LAYER_2:2]
[LEVELS_ABOVE_LAYER_3:2]
[LEVELS_ABOVE_LAYER_4:2]
[LEVELS_ABOVE_LAYER_5:3]
[LEVELS_AT_BOTTOM:2]
[CAVE_MIN_SIZE:1]
[CAVE_MAX_SIZE:1]
[MOUNTAIN_CAVE_MIN:2]
[NON_MOUNTAIN_CAVE_MIN:4]
[ALL_CAVES_VISIBLE:0]
[SHOW_EMBARK_TUNNEL:2]
[TOTAL_CIV_NUMBER:5]
[TOTAL_CIV_POPULATION:13000]
[SITE_CAP:100]
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:0:0:0]
[RAIN_RANGES:0:0:0]
[DRAINAGE_RANGES:0:0:0]
[SAVAGERY_RANGES:0:0:0]
[VOLCANISM_RANGES:0:0:0]
[PS_EL:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:330:299:299:299:330:299:299:299:330:299:299:299:330:299:299:299:299]
[PS_EL:99:99:99:99:99:99:99:99:99:99:99:99:99:99:99:299:299]
[PS_EL:299:299:299:299:299:299:299:299:299:299:299:299:299:299:99:299:299]
[PS_EL:200:99:99:99:99:99:99:99:99:99:99:99:99:99:99:299:299]
[PS_EL:200:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:200:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:200:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:200:99:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:200:200:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:200:200:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:200:200:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:330:299:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:99:99:99:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_EL:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299:299]
[PS_RF:36:10:36:36:10:36:36:10:36:36:10:36:36:10:36:36:10]
[PS_RF:90:67:28:67:90:67:28:67:90:67:28:67:90:67:28:10:10]
[PS_RF:3:3:3:3:3:3:3:3:3:3:3:3:3:3:3:36:28]
[PS_RF:100:67:100:67:100:67:100:67:100:67:100:67:100:67:3:36:10]
[PS_RF:28:3:3:3:3:3:3:3:3:3:3:3:3:3:3:28:36]
[PS_RF:10:3:36:10:28:36:10:28:36:10:28:36:10:28:36:10:28]
[PS_RF:36:3:36:36:10:36:36:10:36:36:10:36:36:10:36:36:10]
[PS_RF:28:3:10:28:36:10:28:36:10:28:36:10:28:36:10:28:36]
[PS_RF:10:3:36:10:28:36:10:28:36:10:28:36:10:28:36:10:28]
[PS_RF:36:10:36:36:10:36:36:10:36:36:10:36:36:10:36:36:10]
[PS_RF:28:10:3:28:36:10:28:36:10:28:36:10:28:36:10:28:36]
[PS_RF:10:10:3:10:28:36:10:28:36:10:28:36:10:28:36:10:28]
[PS_RF:90:3:3:36:10:36:36:10:36:36:10:36:36:10:36:36:10]
[PS_RF:3:3:3:28:36:10:28:36:10:28:36:10:28:36:10:28:36]
[PS_RF:10:28:36:10:28:36:10:28:36:10:28:36:10:28:36:10:28]
[PS_RF:36:10:36:36:10:36:36:10:36:36:10:36:36:10:36:36:10]
[PS_RF:28:36:10:28:36:10:28:36:10:28:36:10:28:36:10:28:36]
[PS_TP:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:40:-300:40:-300:40:-300:40:-300:40:-300:40:-300:40:-300:40:-300:40]
[PS_TP:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:60:60:40:40:40:40:40:40:40:40:40:40:40:40:40:40:40]
[PS_TP:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85]
[PS_TP:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85]
[PS_TP:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85]
[PS_TP:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85]
[PS_TP:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85:85]
[PS_DR:36:1:36:36:1:36:36:1:36:36:1:36:36:1:36:36:1]
[PS_DR:12:100:27:100:12:100:27:100:12:100:27:100:12:100:27:1:1]
[PS_DR:3:3:3:3:3:3:3:3:3:3:3:3:3:3:3:36:27]
[PS_DR:34:100:34:100:34:100:34:100:34:100:34:100:34:100:3:36:1]
[PS_DR:27:3:3:3:3:3:3:3:3:3:3:3:3:3:3:27:36]
[PS_DR:1:3:36:1:27:36:1:27:36:1:27:36:1:27:36:1:27]
[PS_DR:36:3:36:36:1:36:36:1:36:36:1:36:36:1:36:36:1]
[PS_DR:27:3:1:27:36:1:27:36:1:27:36:1:27:36:1:27:36]
[PS_DR:1:3:36:1:27:36:1:27:36:1:27:36:1:27:36:1:27]
[PS_DR:36:5:36:36:1:36:36:1:36:36:1:36:36:1:36:36:1]
[PS_DR:27:5:3:27:36:1:27:36:1:27:36:1:27:36:1:27:36]
[PS_DR:1:1:3:1:27:36:1:27:36:1:27:36:1:27:36:1:27]
[PS_DR:12:1:3:36:1:36:36:1:36:36:1:36:36:1:36:36:1]
[PS_DR:3:3:3:27:36:1:27:36:1:27:36:1:27:36:1:27:36]
[PS_DR:1:27:36:1:27:36:1:27:36:1:27:36:1:27:36:1:27]
[PS_DR:36:1:36:36:1:36:36:1:36:36:1:36:36:1:36:36:1]
[PS_DR:27:36:1:27:36:1:27:36:1:27:36:1:27:36:1:27:36]
[PS_VL:99:99:99:99:99:99:99:99:99:99:99:99:99:99:99:99:99]
[PS_VL:99:99:99:99:99:99:99:99:99:99:99:99:99:99:99:99:99]
[PS_VL:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_VL:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51]
[PS_VL:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_VL:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51:99:99]
[PS_VL:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_VL:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51]
[PS_VL:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_VL:51:50:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51]
[PS_VL:99:50:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_VL:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51]
[PS_VL:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_VL:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51]
[PS_VL:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_VL:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51:99:51]
[PS_VL:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99:2:99]
[PS_SV:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:26:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:26:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:40:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:67:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:40:100:100:100:26:100:100:100:100:100:100:100:25:100:100:100:100]
[PS_SV:40:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:40:25:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:25:25:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:0:26:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:26:26:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:100:100:100:100:25:100:100:100:100:100:100:100:25:100:100:100:100]
[PS_SV:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
[PS_SV:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100:100]
The main difficulty in genning Somthur was those damned megabeasts wrecking everyone but goblins (all hail their demon overlords!)
However, I suppose megabeasts were not truly asked for, and multi-z embarks are bit of a pain without twbt. Here's another theoretical idea:
In the year 2016 of Moÿoanenu, there are joyous mountains, deserts & forests, accompanied by black hole glaciers across 2z. Did I mention war?
Namely, war between humans and elves and goblins and elves. The elves are losing, badly, holding only on to their biggest forest retreat. Everyone just seems to ignore the dwarves unless the gen puts elves near them for some reason?

(You can perhaps get that black hole glacier coldness via biome airspace shearing - way more harmful than most evil rains, and lots more FPS efficient.)
(silty clay
)
(I love the layout of murky pool + olive and fruit trees)
(The caverns have the first deep pit I've ever seen, and also a downward passage.)
They only own the big forest retreat, with about 300ish sentients. The human town has ~3k, mostly human, while the nearest goblin fortress has 2,5k trolls, beak dogs and 6,5k goblins. (this is not the best result but I learned that worldgen discards old world gen params...>_>)
Oh yeah, and I dig into each of the biomes and found no iron (a little weighty, though, like 70z total from bottom of hell to highest reaches of sky. 3 caverns, however.)
[WORLD_GEN]
[TITLE:Cracklife2]
[SEED:AH01AkKIIXqUPLH4IEKZ]
[HISTORY_SEED:sGBOJlN1sVpqhbfh9spK]
[NAME_SEED:6MU8Y40wOeEqSYSKuSWS]
[CREATURE_SEED:USuSe2kYWw0SmKM6A8sO]
[DIM:17:17]
[EMBARK_POINTS:1503]
[END_YEAR:2016]
[BEAST_END_YEAR:1000:-1]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:1]
[ELEVATION:99:330:0:0]
[RAINFALL:0:100:0:0]
[TEMPERATURE:-250:100:0:0]
[DRAINAGE:0:100:0:0]
[VOLCANISM:0:100:0:0]
[SAVAGERY:0:100:0:0]
[ELEVATION_FREQUENCY:1:1:1:1:1:1]
[RAIN_FREQUENCY:1:1:1:1:1:1]
[DRAINAGE_FREQUENCY:1:1:1:1:1:1]
[TEMPERATURE_FREQUENCY:1:1:1:1:1:1]
[SAVAGERY_FREQUENCY:1:1:1:1:1:1]
[VOLCANISM_FREQUENCY:1:1:1:1:1:1]
[POLE:NONE]
[MINERAL_SCARCITY:1000]
[MEGABEAST_CAP:0]
[SEMIMEGABEAST_CAP:0]
[TITAN_NUMBER:0]
[TITAN_ATTACK_TRIGGER:20:0:0]
[DEMON_NUMBER:15]
[NIGHT_TROLL_NUMBER:0]
[BOGEYMAN_NUMBER:0]
[VAMPIRE_NUMBER:20]
[WEREBEAST_NUMBER:20]
[SECRET_NUMBER:1000]
[REGIONAL_INTERACTION_NUMBER:0]
[DISTURBANCE_INTERACTION_NUMBER:0]
[EVIL_CLOUD_NUMBER:25]
[EVIL_RAIN_NUMBER:0]
[GENERATE_DIVINE_MATERIALS:1]
[GOOD_SQ_COUNTS:21:0:200]
[EVIL_SQ_COUNTS:0:50:0]
[PEAK_NUMBER_MIN:0]
[PARTIAL_OCEAN_EDGE_MIN:0]
[COMPLETE_OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:0]
[REGION_COUNTS:SWAMP:0:0:0]
[REGION_COUNTS:DESERT:0:0:0]
[REGION_COUNTS:FOREST:0:0:0]
[REGION_COUNTS:MOUNTAINS:0:0:0]
[REGION_COUNTS:OCEAN:0:0:0]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:0:0:0]
[REGION_COUNTS:HILLS:0:0:0]
[EROSION_CYCLE_COUNT:30]
[RIVER_MINS:0:0]
[PERIODICALLY_ERODE_EXTREMES:0]
[OROGRAPHIC_PRECIPITATION:0]
[SUBREGION_MAX:5000]
[CAVERN_LAYER_COUNT:3]
[CAVERN_LAYER_OPENNESS_MIN:70]
[CAVERN_LAYER_OPENNESS_MAX:90]
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:10]