You might want to run this situation by an attorney. At some point, you may need back up from law enforcement. Forget about ending this involvement in a graceful way. There's going to be some ugliness. I know you have a ton of stuff to get off your chest, but don't waste your breath. He has zero interest in any "discussion" you might imagine having with him. You would be talking to yourself.

His mom living across the street might be a good thing. At least it gives him somewhere to go. Once you get him out of the house, change all the locks and never let him back into your home. Don't even talk to him, if you pass him in the street. Stop taking any money from him. Good luck.