Slavery most definitely is allowed by the Jewish and Christian God. Genocide is much trickier, as there is still debate about certain wording and whether or not genocide actually happened at the time. Overall, the consensus is that genocide is bad at current times either because all genocide is bad or because God does not condone current genocides.
Source: I'm Christian
Don't forget Ehud, the immensely fat guy from the Bible who was stabbed while taking a dumb.