Kitten or Catpeople mods will never be allowed in my mod. HA.
Anyway, yes, smake, you solved a problem with a solution so very simple, I completely overlooked it. I always wanted to make different embark races, but was afraid how that would mess up the balancing in worldgen and the trading/sieges of elves, humans or drow.
The solution: Keep them as they are, and write a new, playable version. You did not change the existing orcs, you wrote a new entity. I can just copy the elves, write a playable version, and keep it out of the raws while people play dwarves. Then they press a button in the launcher, and the "normal" elves are replaced by playable elves, with all the custom buildings and reactions. And it wont mess up trading or balancing, because it is your own civ. So yes, I am playing with the idea, but it should be a long way off, because of all the custom buildings and reactions for 3 races. Should be fun ^^
To take some animals away from them, remove these lines:
[USE_ANY_PET_RACE] < takes pet_exotic at embark/caravan
[USE_CAVE_ANIMALS] < takes subterranean at embark/caravan
[USE_EVIL_ANIMALS] < self-explanatory
I would cut out some of the more dwarven specific stuff, and if you need any help with reactions just leave me a PM. Nobles... I dont know much about that, I tried that in the beginning, but they were broken somehow, but as someone said: toady fixed some stuff on them, so maybe it is worth another try.
EDIT: Oh, and the caste specific sprite trick? Forget about it, works only on invaders.