A backshot is a shot in any sport which knocks a ball backwards.
yes
Yes you can. Using vibrater or toothbrush or any object that feels good .
Back shots can make your butt look big. You can try taking shots in more of an angle to make your butt not look as big.
There is no such thing as a "backshot" in pool. The question may refer to draw of a cue ball or a "kick shot". In both cases, there is no limit to using draw or kick shots in pool except on the break, when one of the first 2 ball at the apex must be struck by the cue ball.
yes