Hrm. Maybe. But she's magical in nature too, and he'd have a hard time ever hitting her between her teleportation powers, phasing powers, flight, TK, etc. Eventually I have to believe she'd figure a way to get to him.
Erm, Raven has some hardcore showings though. Not just the Trigon story arc either. She's owned the entire Titans roster on more than one occasion, and has a few cool mass-teleports and phasing feats that make me believe she'd get his helmet off. The whole emotional side-trips are more left for the TV show. She has them in comics too, but it doesn't stop her from kicking ass when she needs to.
And using her emotional problems as a defense is like saying she loses because of a plot device. It shouldn't really hinder her under most circumstances.