Participating in activities that involve self-harm should hardly be illegal. They're not very smart and probably shouldn't be practiced by personal preference, but if it your preference to do so than the law should not have any right to restrict you in that regard. If you want to cut yourself, fine, go ahead, do it. If you want to drink and destroy your own liver or smoke and get lung cancer, fine, that is your prerogative. It is only when these activities begin to hurt other people that they become truly wrong and that's why we have laws regarding drunk driving and disorderly conduct. I'm not sure what legislation may or may not exist that pertains to secondhand smoke, but if there isn't one I'd be all for it. Actually outlawing drinking and smoking, though, would be a very bad idea.
Don't forget that Nicotine and alcohol are both addictive - laws that prohibit drinking don't take into account the fact that people who are addicted will get cravings that would influence them to commit what would then be crimes in order to obtain what their bodies need. You can offer all the rehab in the world for people who would then be guilty of Nicotine or alcohol-related crimes, but there's no way you'd catch all of them and you'd simply be increasing crime rates. Let people drink and smoke, so long as they're not harming other people with it, and once they start to harm others, arrest them. Attempts at preventive laws would most likely go too far and just create newer, bigger problems. Seriously, read about what Prohibition did to America the first time around - it'd probably be a whole lot worse this time.
Don't get me wrong, I hate alcohol on a personal level. I'm a teetotaller, have been my whole life and plan to remain so for the rest of it. I detest the drinking of alcohol and I wish that it would stop, but realistically there's no good way to eliminate it. For now, donate money to MADD, SADD, rehab centers, and Temperance Awareness groups out there that spread information on why alcohol and alcoholism is bad. If you can get the alcohol and Nicotine culture in America to slow down you might have an argument for banning the two. Until then you'd just be messing things up even worse.