Ok, lets give this a shot.
1) I would target aspiring fashion models. Why? Well, they want to use their bodies to display some fort of clothing art. And so i would twist this into killing them and exposing the bodies wearing humiliating/sexual garment.
2)My M.O. would be kidnapping the girls and having them drink some aphrodisiac potion, and then tempting them into agreeing to my vile purposes as i drown their minds in sexual hormones and pleasure granted by playing with their genitals and fantasies. Finally granting them a swift death upon orgasm, so i could get their orgasmic facial expression "in stone" so to speak. Then, depending on my mood, i would impale them on a pole and pass an iron nail through each nipple, connecting them with a heavy iron chain and fill their mouths with piss. The only consistent feature though would be the happy facial expression.
3) The hands (from the elbow down) and legs (from the knee down).
4) I don't know.
5) Nope. That's all.