O_O This thread scares me. In the approximate words of someone far wiser and more fictional than me:
Gandalf said:
Many that live deserve death, and some that die deserve life. Can you give it to them? Do not be too eager to deal out death in judgment. Even the very wise cannot see all ends.
If I could kill anyone, free of consequence, I still wouldn't. They're another living, breathing, thinking human being, and I don't think I'm capable of what it would take to end a life. The only circumstances I could see myself even getting angry enough would be if someone killed someone dear to me, and even then, I don't think I could bring myself to do it. Death is far too final for it to ever be the right punishment, in my opinion.