i'm wondering when my roommates are going to neuter theirs as well. he is around 5 or 6 months now and hasn't even had his first shots or wormer or anything. he's never set paw in a vet's office. we don't worry about him getting out, unless he happens to decide it's safe to sail off the balcony (we ARE only on the second floor, and there is a female cat living behind us that has at one point been very pregnant).
i had one intact male that began spraying, when i was younger. my mom took him in to get neutered after he went to town on one of her leather jackets one day. he did stop after that, but that's all he stopped.
i don't know if it can help anything else? i never really paid much attention to those things in cats. my cats almost always came in already altered. i have noticed distinct changes in the kitten here though, since his little dudes have dropped. i don't know if that's coincidence, just part of growing up, or directly related to said little dudes. i've also never met a cat so immune to training of any kind. it's starting to feel like i should just stop trying.