Steve, I feel for you. He apparently is trying to hunt the whole property and step over the line and see how far he can go. I'd meet him face to face and discuss things.
As for him being on disability and hunting.....that's bullshit but happens all the time these days. I'd let SS know about it as I see it as stealing and fraud. What a POS!
This is a bit bothersome. I understand there are people with true disabilities. I get it. BUT, if my back was so bad I couldn't work I would think hanging stands would be an impossibility. Riding a quad would probably aggrevate it as well. Just makes you scratch your head. I won't judge because I am only hearing part of the story. Not saying you are making it up. Just saying there can be more details you aren't aware of.