I bet one of the first bugs to come out of this will be that bone crafts will come to life.
I highly doubt that, as you are changing the type of item in the game when you change a bone into a stack of bone bolts.
You maintain the material type (goblin bone), but it stops being "Ulspa's arm bone" (Ulspa being "dagger"/"Urist" in goblin) and becomes a "goblin bone bolt", instead.
You can also see this in things like fish - capturing a fish in a trap changes it from vermin into an item, and hence, if you catch and release a fish, it will simply sit in the pond and eventually rot, because it isn't a vermin fish anymore.
Also, as far as entropy re: creatures, I'd beg to disagree. There is a font for these creatures, and it is the womb. New critters are born naturally and the game keeps track of them all through worldgen. Only at the real-time stage does this effect disappear. Plans are already set in motion to put worldgen simulation things into effect globally, so I'd venture to say that we shouldn't worry about this either.
This doesn't happen nearly enough, however.
Aside from the protected livestock creatures, how many creatures are actually born in your fortress? How many die or are butchered?
Or, more to the point, how many dwarves die in your fortress? How many dwarves are
born in a fortress, and then last long enough to hit adulthood?
How many creatures manage to live through worldgen, and about what is the stable rate of birthrate and deathrate in the worldgen right now? Compare that to how fast things die when an adventurer is around. If we have cities with crypts filled with zombies that regularly have a random zombie pop up in the middle of the street and gnaw on a random few peasants when they are just close enough to the player to be active and attacking things, how do things work?
Right now, we have the game protect megabeasts just so that they'll be alive for the player to kill himself. They don't respawn at all.
The difference in the equilibrium of worldgen mechanics and adventure mode mechanics means that an adventurer actually playing and being near things, so that random animals and monsters and humanoids can see each other and kill each other means that an adventurer is a walking mass extinction event, even without the player actively trying to be one (and they probably will).
The population is simply too small, and the player, simply by
being there, and hence running a different type of simulation than the worldgen-type simulation, has too much of an impact on the global population levels to really be sustainable.
(And because I am suddenly reminded of it...)
806. My character cannot have a noticeable impact, positive or negative, on a town's population.