I think I'm in the minority here, but I don't think anything I know about him (except the police report from his ex-girlfriend) screams, "I'm going to kill someone someday." He was in a charity club and a club that promoted things Asian. Heck, maybe he had always wanted to go to China - I took Russian in high school because the class made a trip there and I wanted to go -- I had no deep interest in the cold war or in the Russian language for that matter. I wouldn't take high school clubs very seriously.
Except for that one picture where he's staring straight ahead at the camera, I don't think he looks like anything but a normal Connecticut boy. The type I wouldn't notice in a bar or on the street -- pick a six pack of people and put them in the scene -- that type. Someone his age might think he's cute.
The stuff his girlfriend wrote smacked to me of a girl who's in a relationship with a boy who isn't as into her as she is to him (the crack about how they're just living together for financial reasons - ha ha ha - and some of the other stuff defending his reputation).
Even the control-freak thing at work doesn't seem that weird to me. I mean, it may be obnoxious, but it doesn't seem that weird - people who don't feel powerful will try to exert control over small things sometimes.
I think it's only in hindsight that these things take on anything ominous. Seems very, very normal for a 23/24 year old high school graduate living in Connecticut, other than the crime he may have committed.
I agree with a lot of what you say. Is it possible that he did like "Asian" things, i.e. food, culture, women? Absolutely, and it sounds like perhaps the fiancee may have been just a little worried about that.
I posted on her thread about how it sounded like, in her MySpace blog, she was trying to convince herself that he wasn't involved with someone at the lab, not trying to convince others.
I really hope they decide to di further into what role she may have played in all of this.