Did you break a promise to eat the steak with him? What's the real story behind that? Was going out for that dinner a big plan between you two, and then you let him down? Or did he know all along that you wouldn't be going? Try not to tell your side of the story, say what actually happened.
I think the guy is a bit ridiculous for ignoring you this whole time, but I wouldn't be very happy if my roomate was looking at porn. I just checked out
www.entensity.net and you have to admit, there are pictures of naked people there, even though parts are blurred. I wouldn't want my roomate to look at that while my girlfriend was in the room. Artistic like some parts of the TFP, or humorous like that site seems to be, either way I wouldn't like it. All that needed was for him to mention to you later that he didn't like that while she was around though. Ignoring you this whole time may be the result of not eating steak and looking at porn and him being overly meladromatic, but I get the feeling that it's a lot more than that, that he's annoyed about stuff you're unaware of. I don't think everyone in the world is just plan nuts, goth, or overly emotional, I think most people are normal and he's probably pissed off about a lot of stuff that you don't know you're doing.
I don't know why you feel like you have to mention your weight and your strength. If you're feeling the need to bruise this guy then you're even more nuts than he is. Sorry, but that paragraph and putting your career goals in jeapardy just came right out of nowhere for me. "You're ignoring me, so let's have a fist fight"?
Next time you see him, apologize for the things you know he didn't like, and then the ball is in his court. Start your plans to move rooms in a few weeks like Janey says, and if you two can work it out before then, then you can choose whether to move. If he doesn't want to talk then go ahead and move.