Your cuddle munchkin is so darned cute!

There's nothing cruel about enforcing indoor-only rules on a cat. And depending on the environment it may be very kind indeed. (In our area outdoor cats are often attacked by coyotes or hit by cars.) It's certainly kind to the many species of songbirds who are often preyed on by wandering housecats.

As for neutering: also kind; do it. The world has too many strays and ferals as it is. You'll also avoid the issues of his going into heat, of which there are quite a few.