Hey Shadowclaimer,
I just wanted to know, if you also intend to give each entity one or more unique Workshops? I guess that could complicate things a lot, but it increases the different feel you get from playing different civs very much, I guess.
Maybe it is even possible to give certain civs access to special materials?
Like give the Frost Dwarves an reaction of "sacrificing" booze, food and fur (or whatever) for a special Metal (e.g. Bifrost) that has awesome stats and is very useful.
Also, I would suggest, that you expand the poisons of vanilla df (similar what to MWDF is doing, maybe even more) to be easily applicable, as several civs of yours really fit in the poison theme. Just make poison-farming more easily doable through maybe some new plants (or poisons to be created from combining existing plants) and you're good to go.
Are you also intending to design special pets for every civ? In this area I might even be able to contribute some work. Tell me, if you want/need help in this area.
Additionally, as someone might have mentioned, some makeshift GUI might be useful for selecting the races you want in your game. If you leave just everything enabled, you might run into problem with embark, where your frost dwarves get to embark with firebirds or something like that.
All in all, keep up the good work, this is indeed a large mod, but certainly very flavourful.