Just curious but atleast one of the skins here uses bump mapping to make it a little more 3D-ish. I was wondering if the same bump mapping is/can be applied to "Genetic" skintone skins...

If so, is it then possible to bumpmap a nude skin to give the impression that certain parts are protruding, when in reality they are not?

Well, from what I senn no ... the bump map is its own .bmp file and some meshes have then and others dont and skin do not have then.

But it was a skin I saw that was modified, so that the "perky nipples" showed, it's one of the skins off this site here.. the "Sexy pink teen outfit with g-string v1.0" has a bumpmap for it, thus why the perkiness.. So skins can have them.. my question is can genetic files (like skintones) have them...

But that's what Drakron said:

"some have them and other's don't and skins do not have them."

So the answer is no at this point.

What if you made an invisible top, by blacking out the alpha file, but include the perkiness in the bumpmap? Does the blacked out alpha file cancel out the bumpmap as well as the texture? Probably.

If you make the texture transparent, you have no bump effect, because the bump effect is simulated by adding shadows to the texture itself and there is no actual displacement. You should use a "displacement" map instead, but the game does not support that.
Anyway, there must be some way to add bump maps to the nude textures, most likely by editing txmta files and eventually adding items to the packages.

I am working on this project and will keep you informed.