sometimes it is best not to know what our little angels are up to when they go out. As long as they are neutered by the time they venture out just leave them in peace to wander.
I live in a flat in a town centre, this restricts the type of cat that I can have. I adopted my last thug when he was quite old and just wanted a quiet life, he stayed in the house and toddled around his estate.
The question of 'indoor' or 'outdoor' cats is a no winner, we will never all agree. Bit like 'stay at home mother' or 'working mother'.
Good luck, you'll need it - kittens are monsters, cute little lovable monsters but still monsters.