He probably feels safer on higher levels. Once he gets used to his surroundings and feels comfortable he'll probably come down to floor level. I wouldn't worry too much, especially if he's eating the raw food, which I assume has a lot of moisture in it. The reason I try to get my cats to eat mostly canned food is because it has so much moisture in it. Raw food is even better, assuming it's made properly, and I just don't have the time or patience to do the raw food thing. If you can put a bowl of food on a higher level for him he might drink some.
As far as sutures, I never had any issues with my boys. Three of the girls had been spayed shortly before we got them, and Daisy had two stitches dehisce, but the boys were no problem. Some cats, though, including several of mine, just plain feel lousy after their vaccinations.
