You don't sound cold-hearted and judgemental to me. You sound like you are looking at the situation logically/practically. You don't want to take on a guy that has issues, when you are trying to get your life to better place and attain your goals.
To be honest, what he did sounds very immature and well.....messed up. I'd be really pissed if someone did that to me.
I also worry that it could be a red flag indicating that he is possessive and could turn potentially abusive at some point. I don't get how he thinks he has the right to tell you he is jealous of you talking to another guy in front of him when the 2 of you are not in "a relationship" (due to him not wanting to be in one). Tread carefully..... I know you like him a lot but you may not have seen all the sides of him yet. I REALLY don't like what he did online, pretending to be someone else. That was pretty low and weird, and even creepy IMO.