Sneezing could be a sign of snuffles, suffles is caused by bacteria called pasteurella multocida, but some other bacteria can also cause an upper respiratory infection. Have you seen any thickish, white or otherwise colored snot around his nose? That would be another sign of snuffles. Do you hear any wheezing at all when he is breathing harder than normal, for example when you clip his nails?
Snuffles can lead to head tilt, it’s when the bacteria invades the middle ear. So it’s really good that you’re taking him to the vet, if he has a respiratory infection, he can be put on antibiotics and that would greatly reduce the risk of head tilt. The vet will listen to his lungs and they will hear if there’s a breathing problem, antibiotics help against that too.
The little red spots are puzzling though. Sore hocks tend to start as calluses. That’s bared, glossy pink skin that’s hardening, most commonly under the heels. Were the spots on his fur or were they spots where he had no fur? Red pee can stain bunny feet, if your bunny is light in color.