With regards to female and ethnic soldiers, it seems like that problem could have been avoidable if a Sim City 4 style rendering technology were used:
http://i.imgur.com/vJ960.jpg
I'm not sure if this is currently being used or not at the moment, or how much performance it would save for Xenonauts, but there you go. Having been part of the SC4 mod scene, these things can get really really complex.