Will neutering my 4 year old Pomeranian calm him down?

We have kept him intact for breeding reasons, but he has been diagnosed with black skin diseases (which is hereditary) so we cant breed him. The problem is he marks on everything, barks constantly, and is showing signs of aggression. Will any of these behaviors stop with neutering? We have been dealing with them for years now, because we wanted to stud him out. I have been told that these behaviors will not stop because of his age. So I was hoping for someones personal experience on this. Thank you