You should wait till he's 6mo of age to have him neutered. At the vet clinic I work for we won't do a neuter or spay befor 6mo. As Crittercall said , they get some of their hormones from there reproductive organs. Besides Males are not the only ones who will spray, Females do it also. And even if the male is neutered they can start sraying at anytime. But the older they are the more it is likely, especially in a multiple cat house.
As far as declawing, if you decide you want that done, do it anywhere between 12weeks and 6 mo. It's easier on kittens then waiting until the kitty has become a cat of a year or so. An older kitty tends to bleed more and be more tender footed afterwards.