I love those ideas. I also agree that we have a solid beginning. We need, however, more internal and external possibilities that really are superfluous in the beginning, but become more important later on.
Like Sapidus was saying, when you're up to 43 dwarves and 20 of them have beds... Why on The Continent of Drunken Leaping don't we see dwarves simply refusing to work? Dwarven protests? After the economy starts, I know we have coins... But what are they for? What about more nobles? Shops? Right now as it's an alpha, we have a great chance to brainstorm about what the economy really should consist of and what consequences a player could suffer for not complying.
I really hate to see my dwarves get beaten or carted off to luxury prison (really, prison's like a vacation) just because some brain-damaged Urist McButtplug doesn't realize we don't have rose gold, let alone normal gold to MAKE rose gold with, anywhere to forge him a damn throne out of it. Right now, you realize, that is the economy.
After the economy starts, dwarves should want to get paid for their work... Which means you'll need to mint coin. They could buy trinkets with coin and whatnot and, of course, food and drink. No coin? No sustenance! Unhappy dwarves result. They then decide to simply steal from the stores. Now my Captain of the Guard is VERY happy as she finally gets to detain TRUE wrongdoers and not just the poor sap my braindead nobles decide to point at.
In the beginning, every dwarf may be content with a barracks to sleep in... But after 20 or 30, it'd start to get cramped. Why wouldn't they want individual rooms? With a cabinet and a coffer to store their things? Whatever happened to rent? Right now it just seems to calculate how "good" a room is for your nobles to fight over who gets the masterwork chests and cabinets. Having higher rent and having a tax or rent collecting noble (treasurer!) to collect and evict those that default would lead to players needing to decide how to better structure their quarters. Low rent wouldn't be "make and then obsolete" anymore. Poorer dwarves would need it.
Haulers and craftdwarves should be paid for their time from the fortress coffers. If we ever can shut off noble migrants and just pretend we're starting our own brand new dwarven civilization, this might be the mayor or regent's coffers. Value should be separated into material value and quality value. Within a fortress a dwarf might be able to buy a high overall value item for just a little over the material value, but traders need to pay full price. This would be so your legendary cooks don't overcharge for their masterwork prepared foodstuffs.
If you have a brook and "widen" it to a river (IE destroy the brook tiles via channel) then you should be able to see boat traders. Maybe vikings (or applicable boat-riding loot-and-pillage raiders) could ravage your settlement. We could have trip-levers or somesuch to retract bridges to allow the boat traders in or whatnot.
Migrant animals! My maps are being hunted bare which highly impacts late game. I also think magma creatures should "flow" into the map the same exact way magma does... From the bottom of a vent. They shouldn't run out ever. Tapping and exploiting a magma vent is far too easy, even with temperature on. There should always be a constant threat of incursions by at LEAST lower tier magma creatures (imps and magma men) every once in a while. Migrant monsters too! I have sieges off and, even though I'm really not too much into the military aspect of DF as I just like carving out a nice place to live... I think goblins (thieves and child snatchers and lower tier attackers) should just pop in once in a while. They should pop in with no intent whatsoever... If you're adequately hidden they just meander on their way. If you aren't, you find yourself dealing with a little annoyance. If they escape, expect a siege (if you have them on) or two.
I also like the idea of nature-based monsters. Although not originating from the map, just arriving to investigate the cries of the wild. Lower-tier at first, of course. Gaia Pups, Golem Minora, and Neophyte Treents oh my! If you let them escape, you should expect a nature-based siege (again, if you have them on) from the Gaia Wolves, Golem Majora, and Grown Treents! Maybe an elder will show up to smack you around.
As you can see, all of these are fairly intuitive additions and, in the case of the roving monsters and animals, they are easily scalable to how bad you want it... If you don't want the bad sieges, turn them off. Related to my "Migrant Toggle" thread, perhaps we can see a few more toggles... Like so:
Migrants - on/off
Self-explanatory. Likely would fix popcap problems and allow popcap to actually define overall population maximum, not migrant maximum.
Noble migrants - on/off
If they don't come, you assign them. Independent from migrant toggle.
Caravans - on/off
Self-explanatory
Raiders - on/off
Don't want goblin raids (not sieges!)? Turn them off!
Sieges - light/medium/heavy
More differentiated siege toggle allows to set the upper level of siege difficulty.
Economy - simple/normal/complex
Differentiated toggle allowing players to choose their economy settings. Simple would function much like now, except with stores simply handing out food and things. No purchase, largely communistic. Normal incorporates coin and a flat rate for all products bought in fortress. Complex incorporates material value, requiring differentiated products to be made.
Lifespan - short/normal/long/inf
Obviously a toggle to modify how long critters live before they die. Short could be something like .5 multiplier, normal would be 1, obviously, and long would be 1.5... Inf would be, obviously, aging yet immortal (unless eaten by that dragon, stabbed by a goblin, burnt to death by a fire imp... Ahh, you get the idea) dwarves.
This is only the beginning of the plethora of enhancement ideas I have had brewing for DF. Although posting them has largely gotten them ignored... Oh well. ;P