Honestly, the question is not for you to ask "Should I rent out rooms in my house to friends", but for your friends to ask "do I want to live with a guy who has a massive personal interest in the well being of this structure we live in"
I mean, I know friends who own their own homes, and rent out the spare rooms to good friends who they get on impeccably with, and even in cases where they would make basically the best housemates in a rented house, there are always conflicts, because you will inevitably have a great deal more respect for the house than they will, even if they are reasonably clean, tidy people.
I've had wildly varying experiences living with people who owned their own house. Sometimes the nicest people turned into the biggest anal bastards about little things which caused massive rifts, and sometimes it worked out really well.
Basically, I would recommend it, but I would be very careful who you rent to. Just because someone is your friend, and even just because you've successfully lived with them in the past, or whatever, doesn't mean they will necessarily be a good housemate for a place you own.
Also try not to be overly anal. You obviously have to take some pride in your home, but remember that if you are young, and your friends are young, things might get a bit messy, young people are like that. Also if you throw a decent sized house party, someone is going to break something, deal with it, that is the price you pay for having a bitching party, think of it as an opportunity to learn some valuable carpentry skills.
As for the whole privacy thing, just pick people who you don't mind having around constantly, or people with completely different timetables. I personally love sharehouses, they're like crack to me, so I might be biased though. I got a little tired of them and moved into an apartment with another person who keeps different hours to me completely, and that I rarely see, and now I just miss coming home from work at 6 am in the morning to find a group of people still awake, wasted on gin, punching cones and watching morning cartoons.