Say if you get the cyber, robotic arm thing or whatever it is, and you want a texture on the arm. can that happen?

Imagine it like this: if the item is on top of your body, it covers up the texture thus you can't see it.
To answer your question, yes, you can put texture on your body no matter what 3d items you're wearing, but if the item covers whole part then the texture will simply be covered up.

The 3D item itself cannot be textured. Recolours are available for 3D items, however.

Check this thread for more info on recolours: http://forum.toribash.com/showthread.php?t=572696

You can texturize a 3D item if you create a tga. file.

Example: To texturize head.obj you have to create head_obj.tga

Moved this to a more appropriate section—this doesn't have anything to do with technical support. 8/