First time ever: two posts in one day!
A telepath can't play a fair game of chess. If you play chess against a telepath, he's either training you, or letting you win. Why doesn't this bother anyone (like Erik) playing against Charles Xavier?
A telepath would be a guru on social interaction and psychology. He would tailor manipulative words to suit each person he speaks to, so he'd rarely need to resort to mind control (which gives him an awful lot of power, by the way).
It seems that the writers of "X-Men: First Class" failed to think telepathy through thoroughly. I can think of several things Professor X failed to say to Magneto at the end of the film, and I'm not even a telepath. Like, "Are you trying to create a master race? 'Cause you should have a moral problem with that." If Professor X truly wanted to stop those warheads, he would have said something along those lines. And then Magneto could respond to it with something mind-blowing, and then maybe I would actually believe his sudden character plunge from good-vigilante to tyrant-bent-on-genocide.
Ah well. If believable character development were a priority in Hollywood, this would be a different world.
As for the telepathic diamond lady ... if she has Xavier's power to control minds, she would be the one in charge, not fetching the ice. Sorry, but that's just the way mind control works. It trumps other powers.
FYI for all people reading my blog: I write better telepaths.