Re: High Powered Super-heroes
It varies. I've seen a 250 point character capable of flattening Dr. Destroyer in a single phase (his 4e, high-end version), so that's definitely a 'high powered' character, despite not having scads of points.
Typically, when a new character enters a group, I give him XP equal to half the amount that the most-experienced character has. Generally enough that the character still feels 'new', but so left-behind that he's gimped.