I can't draw in general, but the thing I see most people muck up is noses...
But then noses look weird and out of place/proportion on a lot of people's faces back in the real world, so no big surprize there...
As for the whole modelling thing, eh, i'd go for it if i got paid, but i've got stretchmarks something shocking and am somewhat a man of largesse...
(Oh, and also, i'm in Aus, so i dunno what the rules/laws ect are on modelling in general, let alone nuding up)
But really, for you guys complaining about a model moving, well, Duh! they're supposed to, thats the entire point of it, to see natural poses and movement, if you want something that dont move, ask the model to make such and such a pose, then take a few photo's