About the Haitian, maybe Peter doesn't know how to use his powers yet? No, that'd be stupid. Maybe he can't absorb the Haitian's powers. Maybe no one can. Maybe the Haitian is going to save the world one day.
Actually, yeah. Remember how Sylar's powers weren't working when he was in the same building as the Haitian, so that he had to come out to be able to use them? All they have to do then is take the Haitian to every bad guy's door and kill them, instead of creating unnecessary drama.
Screw the IPL, I'm going to the MLC