I have read varying things. We had a male cat in the house a few years ago that marked certain corners in the house... I'm not sure if he was actually spraying, though.
probably not, sometimes a neutered cat will still spray but this usually happens if he has already developed the habit before being neutered. there is a chance tho. (if im wrong about this someone please correct me).
If they have gotten inot the bad habit of spraying while they are still intact, some neutered males will continue to spray. It like a bad habit that needs to be broken. If it happens, use an enzymatic cleaner to removes the spray (use a blacklight to determine exactly where.) I beleive they also have stud pants (like diapers) that prevent spray from infecting your home.
Neutering takes away a lot of their urges but doesn't entirely eliminate them. If you neuter young there is a great chance that they won't develop the habit. But they can do it, even when neutered young, if there are dominance issues, stress or overcrowding.
All of mine were neutered young before they ever marked. There are times under stress that they will spray until they are settled down. For example, when I adopted my puppies, one of the cats wasn't happy with them for a while and would spray in their kennels. Once we regained the balance of the household, it stopped. I do have 10 cats that live indoors and there is always a low level of stress from having that many cats. Adding the puppies to my mix pushed them over the edge for a while.
It's possible, but very unlikely, that they will spray. We had one male who was castrated at age 8, and he continued to spray. Our current cat is also a male, and was castrated at 6 months. He started to spray outdoors and at one cellar window at age 3 1/2, and has continued to do so, but in response to cats invading his turf.
My husband's cat was 15 when we got married. He was spayed as a kitten though I don't know exactly what age since I wasn't around.
When I moved in my husband's house he started spraying my clothes, lawn furniture in the basement, a workman's shoes.... it was just awful. To top it off he was a very stand-offish cat.