You could, but you would be staring at a lot of work.

For instance, Zgock replaced the V4 head entirely with an anime one (Google for "Zgock Nanana Poser") - you download the results in an RTE file, run that, and he supplies you with a .cr2 and some basic textures to go with it (because the std. V4 head tex won't quite fit the new one, methinks - haven't really tried to that yet).

It's safe to say that if you change the polycount, you basically have to re-rig the whole figure, re-do the UV maps (or hope they work), and suchlike.

--

The whole boob/genital thing is purely subjective; I honestly don't care if someone wants/uses them or not, or for what reason.

/P