Ok I expected this.

First my girl was an indoor cat for well over a year before I neutered her, she never "wailed" to go out, was quite content. She is an outdoor/indoor cat now.

I had a male who is no longer with us but the vet told me to get him neutered as well as health reasons (if he was allowed outside) - he would also not roam too far.
Well I took the advice and since the op he left home and I didnt see him again for 3 months!!! I thought he had an accident but over the next year he would resort to this pattern of behaviour. I would not see him for a few weeks at a time.

I have unfortunately smelt a cat spraying and yes it is the most horrid smell I could imagine and IF my indoor boy started spraying then I would get him done but if that doesnt happen then I wouldnt just for the sake of it.

You cant generalise about cats, I am sure this has happened to yourself or people you know but every cat is not the same. I have had 7 so far (only 2 now though sadly) and I have never had any of these problems.