Will a Nikon SB-700 flash work on a Canon Body?

I can either buy a ~$200 mounted flash or use my friend's, only problem is she shoots nikon and I shoot canon.

Not in any meaningful way.

You lose the iTTL and Commander Mode features

Depends on your definition of "work". Will it fire? On certain Canon bodies, yes. Will you have any control? No way.

It will do in full manual control.

It will work in off-camera slave mode with pocket wizards, but you must maintain electrical isolation by not directly connecting the flash to the camera; or those evil Nikon electrons will destroy your feeble Canon camera.

I think no because you know both are competitors so you can't expect it. But still the machine has other language. It might work on it. But check it before you buy.