He is one lucky cat to have you come into his life. Well done.
My daughter recently brought one a neglected kitten. Georgie was so neglected he took to tearing apart whatever was left on the kitchen counter, namely bread in packages. His ribs were showing and he had an injured paw and I since learned that he was in a home with dogs, and I think the dogs attacked him.
Many vet dollars later, we got him healthy.
It took us a while to teach him to stay off the counters and how to open slightly ajar doors himself. Although if he really wants something that I am preparing, mostly cheese, he will stand up against me and run his claws up my legs, but he does not dig the claws into me. I end up giving him what he wants and so the drama continues.
Unfortunately, he loves to eat and is getting way too fat.
He is such a nice guy to all the other cats that they (the crazies) swat him in the face a lot and he always seems to have a new scratch mark on his face.
Truth fears no question. Anon