I think you need to wait until you have kids of your own. Then you can cross that bridge.

My personal opinion, parents should have certain amount of authority and control over their kids. Unfortunately, it is very hard to both be a friend and the police to someone. It is difficult, not impossible. And also, much as we'd like to escape our parents' parenting style, I think some aspect of it will still be evident in our own parenting style.

Once, my son who's asthmatic, had a cough. The loose, phlegmy sort of cough. We were taking him to his paed, for check-up and see if he needs the neb. When walking towards the clinic, we passed by this family, father, mother, 2 girls. My son, coughing away, caught the father's attention. He said snidely, something along the lines of, how could any parent let a child have a cough like that and do nothing. Wanna guess what he's doing? Smoking. In front of his family. So there.