Whether you drink or not and whether you are an alcoholic or not is personal information in my book. Most "normal" drinkers aren't going to care one way or the other anyway.
In a potential roommate situation though, I would potentially want the fact that you don't drink to be out there...just as you might want to know if a potential roommate is a smoker or a non-smoker.
What you do with your time ( going to meetings, etc ) is absolutely your own business though..and you have no oblication to tell anyone where you are going or what you are doing.