Yeah, you have a young one. He'll either be teething for another 3-6 months and then start to calm down, or he'll just be one of those eternally un-lazy, playful cats. Either way, have fun! Enjoy it while it lasts, lol
Neutering doesn't do much in the way of preventing "spraying," I believe that's just a myth. And cats usually only spray if they're territory is threatened. This usually happens only when you interoduce a new cat to the family. But definitely get the cat neutered if you don't want it running around with all the she-cats and forgetting about life at home (it helps prevent the cat from running away from home)
You don't need to declaw cats, because their claws are naturally tucked into the paw. And NEVER CUT A CAT'S CLAWS (or whiskers). The claws and whiskers have nerves inside them, and to cut the claw off a cat would be the equivalent of chopping the tip of your finger off, right at the fingernail. Pretty painful. The only time cats' claws are out is when they're mad, or climbing a tree, etc. And besides that, some play toys involve the cat grabbing onto it, and this can't happen if the cat has no claws. So I offer a big NO to declawing the cat.
I know a lot of people who have their cats on diets, and only feed them certain amounts at certain times of the day. This is unnecessary labor, unless your cat happens to be an obese diabetic. I just pour food into bowl and the cats come and eat whenever they feel hungry, and they're 13+ years alive and kickin'! I've never had to take any of my cats to the vet either.
Inside vs. Outside:
I'm not a fan of keeping my cats inside, because weird stuff happens when instincts try taking over in a domesticated environment. But at the same time, alot of people hate free-roaming cats and will call up the pound on them. So what I do is I train them to just stay in the general area of my home. Doing this is simple: Just keep them inside for a week or two, until they get comfortable. You then slowly adjust them to outside by, say, taking them into the backyard and playing with them. Let them explore, but not too far! Just keep them close, so that you don't need to chase after them... because you won't catch them. Cats are fast, especially kittens about 10 months old. But when the cat is adjusted to stay around the house, he won't go farther than a couple houses down the street. Now you can keep him outside at night if you want, so he can hunt and play (cats are nocturnal, and they'd be jumping all over the place inside at night), and let him in in the morning.
Good luck and have a great time with your new cat!
I've had maybe 1000 cats in my lifetime... lost count a long time ago.