The more I think about, the more the hybrid clothing seems necessary for this type of thing.  I think even transmapped hair is the way to go, if it can be made to fall like cloth without detaching form the scalp or falling through itself to badly. 

I also think that collision using collison primitives is probably ideal, but not always.

The jiggles plug in for Carrara seems like a way to extend the life of Poser's rigging.  It uses a map to control how much a body part can be affected by a force (gravity in its case).  Poser figures would benefit from softbodies based solely on the frequency with which their body parts self intersect.  I think if I were modeling for realtime using normal maps and maybe even parallax shaders I'd eventually get models that would render as good as "content" figures without the footprint.  

Something like this would be nice, too:

http://www.youtube.com/watch?v=3vrlJFOCbsM