I only kill pirates, and NPC pirates at that. That probably explains why I only have about 60 confirmed kills and am still ranked mostly harmless. Once, in Lave, I got interdicted 3 times in a row. I got so pissed that I bought a fully kitted Viper and scoured the system clean of anybody who was wanted. I got about 10, and it was fun, and then I started thinking about why they would be wanted. Maybe some guy just forgot to pay a parking fine? Then I started feeling guilty.
So when somebody is "wanted", does that apply to unpaid parking fines and little things like that too, or just for serious crimes like murder & piracy? It seems that if somebody is wanted, the only way to collect a bounty is to kill them, so it really means "Wanted: Dead". It might be nice if there was also a "Wanted: Fines", and a mechanism where you don't have to kill them to get them to pay the bounty. And if you do kill those with only fines against them, then you get a bounty for murder on your head. That just seems a little more reasonable than killing someone for anything.
Anyway, since I don't want to be a murder, I only kill in self-defense, although I would like to get a higher combat ranking and more combat experience. Maybe I'll just have to wait for war to come to the Alliance. It seems a bit extreme to not even want to kill NPC wanted players, w/o them shooting first, but I bet there are those that have no kills and always run from pirates, too.