We had a lot of cats over the years, and even the most aggressive older (neutered) male never really hurt a kitten. They seem to know they're babies. Yeah, they may swat 'em good and even scratch a bit, but that's about it. And generally, they deserve it. ;-) Kittens, like puppies, are monsters.
As for neutering, I know Ruthy knows more about vet procedures than I do...but they can do it really young these days. Like two months, I think. I think Tam was maybe four and Halvah a bit more, but they can do them really young.
That's four MONTHS, by the way.
That's cool - It'd be fun to have a kitten.... It's been years since I actually had a kitten. All my cats just sortof show up at the door somewhere between their 4th and 7th life.