"3.) You need to shoot to kill."
That is why one cannot stand over a writhing criminal and pump three more bullets into him / her while squirming on the ground disengaged from the fight.
If the attacker happens to die in the course of a no-bill shooting, that is one thing. To ensure the criminal dies (even though attack was halted) will land an otherwise law-abiding person in legal hot water.
Appreciate the clarification, that's good to know.