Outdoors for the better.
I got my cat when I was 2 years old. He is 16 years old now. He has always liked being outdoors.
We used to live in a very rural area where he learned how to live outside. He was even adopted by a neighbor for a little while until I found him when I was walking home from school one day.
About the bird issue--we had a neighbor who was a bird watcher who was getting mad that our cat was killing the birds in his yard..he actually shot him, but it only hit his tail and he is still perfectly healthy. We have moved twice since then, each time he disappears for 2 to 3 days and always comes back. He's just learning his new environment.
We have lived on a pretty busy street for 9 years now but I wouldn't recommend it for any new or young cat, ours has had a lot of experience, first rural then suburban now semi-urban. I believe if you can't let your cat outside at all, not even in a yard (outside doesn't mean the cat has to roam free), you shouldn't have one.
As gross as it is to dispose of birds and mice on my porch, cats enjoy and live for those chases and games. My cousins have indoor cats that are terribly obese, one died at 9.