It's done, and it wasn't as hard as I thought it would be. I edited the raws to give dwarves Damblock 200, Speed 1, and the no-eat no_sleep, no_drink tags and replaced diurnal with all_active. I used Dtil (thanks Jorgon!) to give me 30 dwarves when embarking. I bought 35 picks (five extras in case something I somehow lost a few), no food, and no animals. I gave everyone max points in miner and created several masons, mechanics and a few building designers (for the supports).
With a speed of 1, dwarves don't move so much as teleport. Even with modest skill, they mine VERY fast, which means they gain tons of xp, which means that they gain skills and stats, which means that they dig faster, which means...
I was able to buzzsaw through the first three mountain layers in just a few minutes. It was amazing. There were some animal attacks, but with 200 points of natural armor, it just didn't matter. I organized a squad to clean up some of the more disruptive monsters. It was quite a sight. You can mark a rally site next to a monster and suddenly there are ten invincible quantum teleporting murder-dwarves tearing the creature apart with their bare hands.
As planned, I rigged all three hollowed out mountain levels to a series of supports linked to a single lever. Pulling it created an impressive dust cloud, as well as genociding all life in the southern half of the map. The dust explosion was so violent that it knocked flying creatures out of the sky. I sent in an euthanasia squad to finish them off before they took wing again.
Clearing the crags around the chasm was harder, because they are basically a bunch of mini-mountains that are connected in complex and unintuitive ways. I had a lot of collapses. It's okay though. I'm pretty sure that the people who died deserved it.
I carefully collected all of the gems and ores that I had exhumed. This did not take long at all. I also created a separate stockpile for "interesting" rocks (basically, any non-economic stone that has a color other than white, grey or black. I like to color code my levers to the things that they control). I'm not sure if I'll actually use the gems and ore when I start playing for real (it feels a bit like a cheat), but I like having the option available.
Something interesting. When I knocked down the first three levels, I did not knock down the caldera of the volcano. I left the volcano and its immediate environs alone. This means that the volcano is now by far the highest object in the game, and that if you breach it at ground level, it will dump two floors worth of lava onto your map. It's quite a sight. I ramped the edges of the volcano to make it more natural looking. This also means that the fire imps can get out and cause trouble, which I like.
This operation generated some 15,000 units of junk stone. It took my super dwarves a little under an hour to chasm it all. The map is clean and pristine.
I made back up saves of the operation at various points, in case I change my mind about something later. I'm guessing that there might be a fair amount of interest in these files, and I'd be happy to share them if someone can recommend a good hosting site.
I've been experimenting with serial reclaim trick. It only appears to multiply monsters that are spawned by special features. I noticed that the chasm, river and volcano monsters increase, but the lone giant eagle just stays lonely.
After three successive reclaims (and a quick use of Dtil's Reveal tool to uncover the rivers), I can report the following monster roster:
31 naked mole dogs
20 troglodytes
6 giant moles (apparently, these are chasm creatures, and not forest denizens like I first thought)
27 cave swallowmen
8 giant cave swallows
27 snakemen
58 frogmen
28 olmmen
29 lizardmen
16 giant crocodiles
16 giant olms
15 fire imps
5 magma men
1 giant eagle (whatever)
I'm not sure what's happening in the HFS because I want to be surprised when I actually play the map. If the HFS are also respawning, I expect to them to kill me so hard that they delete
Dwarf Fortress from my computer.
Unfortunately, Dtil doesn't let you alter the size of a reclaim party (and might I be the first to request this feature?). It's not like it's going to be hard to lose 23 dwarves on a map like this, but keeping the chosen seven from going insane with grief is going to be a challenge in and of itself.
If you don't get arable land, water, and wood, you die. If you go into the forest to get these things, you die. If you try to breach the rivers to get farming and water, you die. If you try hunting in the woods, you die. If you trying hunting in the mountains, you'll eventually get too close to the volcano and then you'll die. If you try tapping into the magma vent to make weapons to fight back with, you die.