Adding my two cents...
When I have kids I fully intend to be a parent and not a friend - however, I'm not going to be like my parents are. I don't want my kids so intimidated by me that they feel they have to hide every aspect of their lives outside of the house. I would like to think that I'll be loving, supportive, and understanding - but not a push over. Oh, and when I'm proud of my kids, I will tell them. When I'm disappointed, I will let them know but I won't hold it over their heads. When they've royally screwed up, I'll let them know but I won't hold it over their heads.
(BTW - the hiding every aspect of your life outside the house from your parents, whom you still live with, will catch up to you. When it does, it will not be pretty. Sadly, I speak from experience...but at the same time, once it does explode out into the open things seem to be a lot less stressful.)
La