He's gorgeous! As long as his weight is proportionate to his build, he's fine. I have had cats that ranged from very tiny to quite large. All but one of them were height/weight proportionate, and he was the only one the vet was concerned about and also the only one who developed serious...
If you must go with the dry food diet, at least supplement it with some canned food. Mix extra water in with the canned food to help increase your cat's water intake, which is a huge plus when concerned about his renal health. You might also try switching to the actual Friskies brand since not...