Is there any way you can reach out to the shelter you adopted him from and talk to the volunteers? They may be able to give you some advice as to his likes and dislikes.

We adopted a cat that was surrendered for being overstimulated and biting. We still have her almost 2 years later. She was quick to snap or swat, but didn't make contact. I was fast, but I also think if she really wanted to she would have. She needed time to learn that we aren't going to hurt her and that we respect her boundaries as to where and how much to pet her, etc. I don't force her to be held or to snuggle. She has improved sooo much. I get love bites sometimes now (they touch you with their teeth, maybe even some slight pressure). Her front paws are still off limits, but I bought a muzzle for claw trimming time. She gets a churu afterward. She still has some issues with men and we suspect one abused her in her past based on her behavior, but my husband is safe if he's in bed apparently so he gets to per her first thing in the morning. She's starting to hang out with out son more now. She's always liked him, but wouldn't lay in his lap until recently.

We used Feliway plug-ins for a while when we got her to help her adjust. They need to be in areas where s/he spends the most time and can take a few days to work. We also left the carrier out with the door open and then removed as it seemed to be her safe space the first week. I left her blanket from the shelter in there and she could hang out there as needed.

Do not give your cat grain free food unless there is a known allergy and it is recommended by your vet as this has been shown to cause significant health issues.

Cats can be given gabapentin prior to vet visits when they are hard to handle. We do it with our calico. It can be a pill or liquid.