i would not kill for money or any other gain. I don't think I would kill for revenge, if someone screwed me over it would prove that they don't give a shit about me so why should I care about them? Jealousy? Meh, if i caught someone with my woman I'd just leave, I have demonstrated that I can get get another.
As far as the rich, I refuse to hate someone just because they have money. If they are hurting people to make more it would seem to be the lesser of two evils... but I just don't see myself killing anyone.
Stealing from people who have everything, contribute little and piss on the little guy is another matter entirely.