It would depend on who I would be killing. But I don't think I would want immortality, because living forever would sooner or later turn into a problem.
I'd do it. Immortality is immortality. I'd either get over my losses and get to experience everything in life, like new progresses in science and go to other planets, or go insane and end up killing mass amounts of people.
I don't understand why anyone would want to live forever, do you have any idea how much you would regret it later on? I would never want immortality for myself.
Wow, this is a tough question. I'd have to agree with Cannibal, because I'm sure at some point in your extended life you would wish you had past away anyways, like a normal human being. Nice Question though.