I think we can assume that's part of it. I'm sure he cares for Denzel a lot and is rather upset he's dying and looks like Roxas.

But Aerith and Zack, yeah, he's hung up. I'm sure he wants to love Tifa but feels guilty too. Especially since Aerith seems to be watching from afar quite a bit, the creepy ho.

I believe at the end of the film this is remedied. He was smilie again. Everyone is cured. His friends showed up when he needed them. He got some closure on the Aerith issue too, I'm think. He saw her and Zack walking away. I'm he sure finally put it together that they were banging each other all the time in the afterlife so he might as well do the same to Tifa.

I'm just saying I'm not sure I would call him emo. I think wrapped up in some problems, but that can happen to anybody. I personally wouldn't call him overboard with it all, but I can see why others would. That's probably because I would get hung up on the past too since I'm just like that. I would be even worse than he is. Maybe I'm an emo! I need tight pants.