Keep that restraining order by all means. Keep your distance too.
Yes, it's possible for people to change, however, I just think there is also a such thing as people burning their bridges. If he does change, he should be man enough and intelligent enough to accept that he ended some close relationships and ties with his troubled time. YOU SHOULD MOVE ON and put him and all of that in the past. Simplify your life and probably add a whole lot of years to it in the process.
A person that just gets angry at things can be helped. but is he an abuser? has he hit you many times, how many times have you been scared, that he will do it again, and what makes you think, that he may change,It really depends what you think, but also think of the children, should they go through this, I have known many womeb that were beaten,many many times, and they were so scared, that they feared for their life, so it really depends, i guess on just how bad he was, i personally would not trust a man that hit me once, I do hope you make the right decision good luck jo