she begins by telling him she a murdering terminator and that she might kill him someday. If she so wanted him to fall for her wouldn't she be telling him the exact opposite?

Yeah there's been a lot of contradictions in Cameron's words and actions, like the stuff you pointed out as well as stuff from earlier in the season. And while I can't quite make it all add up to a total manipulation from the start, it's still my gut feeling. I'm going to be watching her very closely when I go back and marathon the season.

IMO, she leaves in part because she doesn't trust herself with him fully.

Now that I don't agree with. I think she left because of whatever this deal is she was trying to work out with Weaver in the future. Going back to my gut feeling again, I think she wanted John to follow her. But I'll admit that idea really contradicts her breaking Sarah out of jail. The jail break would seem to demonstrate that Cameron knew she was leaving and wanted to make sure Sarah was there to protect John after she left. I've really got my work cut out for me in finding evidence to support my theory :P