I've heard that smoking weed is ok unless you do it in mass amouts. My dad was adicted, and that's part of the reason he's in New York.
Don't instruct him on any tips to deal with anger managment. People say to me "ok, ok zack, take a deeeeeeep breath". It ticks me off
DON"T GIVE UP ON HIM. I say don't be nice to him too fast and out of the blue, but just try to stay out of his way, and then leave him a little note or tell him that you care about his feelings. Ask him how his day was.
Stay with him all the way, and when he hits you again, ask him why. He then might go to his room and think about it, and just leave him alone at that point. Let him come back to you.