Good news is that he and bex get along! Mutual agreement that school can suck and they both like to just grab their rides and go. He's probably raced (on foot) against her truck for sure.
Nah, don't worry about that. Cliff isn't good at sharing, he tries to do it a little more but he's self-concious about things, especially powers. But he'll explain that he has power issues (a little defensively at times maybe) jsut to explain why he's a bit weird at times. He keeps to himself usually, so he doesn't actually mind if she doesn't share. That's cool with him since he's not great at it either.