(Totally not a vent :) )
1)I know that pyromania can be a struggle, you can't control urges. So, in order to fit the headcannon that he's pyromantic; he has social anxiety.
2) He has social anxiety, like I said, but the reason he started smoking is so he could set something on fire in public.
3) He's now addicted to smoking to the point where he had a very bad smokers cough by the time he went to prison.
4) When he set Jeff on fire, the flames flew back and burned his eye, it is a pretty ugly sight so he keeps it closed when he can.
5) He has tried to break up with Keith multiple times, claiming he is dangerous, they both end up crying after that happens. But, of course he has a hard shell and would never cry in public.