Ok, I have murdered many people, sabotaged the rockets, incinerated the NCR at helios one, and the only thing that gives me negative karma seems to be cannibalism. Is this a bug?

its all a matter of perspctive.

killing a random wastelander for no reason= bad karma

kill an NCR= no bad karma, because they are an opposing soldier and your not just killing them for fun or money. you actually agree that your cause is justified and it opposes the NCR

pick a lock in front of someone.

You know the guy who tells you about the sunset star sarsparilla caps? I blew his brains out, no negative karma?

he sold poison milk to school children.

IDK really

Whocares... Karma doesn't play any major... hell even a minor role in New Vegas. It's just there to make you feel like sh1t for killing someone if your the "sensitive" type. Pansies..

I find it hard to gain good karma. I became evil just by thieving (evil, me!), but when I do something like rescue prisoners I don't get any good karma.

Maybe they should just take it out completely.