Next. You get bad karma for killing a good kid (like the sister of the brother who eats his family). You get a little bad karma for even harming her each time you do so, but not killing her, like negative 1 point if say you loose 10 karma for killing.
For kids like the vampire kids, the brother who ate his family, you get Good Karma and a bonus if you eliminate all of them from the wasteland as you prevented their culture of cannibalism and vampirism from taking root and spreading.
Essentially karma in the game would be "Does it benefit the future society or not". If no then its positive, not not its negative, stopping a cannibal tribe is postive.