As far as getting him neutered, that is an excellent idea. If he's litter box trained that is excellent also. On the other hand he is still a kitten. At 6 months he is like a 2 year old. he is still a baby. Sounds like your dog is happy with him and that is a good thing. Hopefully you're not going to get him totally declawed and only frontal. If he would accidentally get outside, he could still at least defend him self some what or at least climb to get away from unwanted predators or bullies. I had cats but that was 3 decades ago. I hate seeing the strays in our neighborhood running from other animals. But first things first, the neutering.