I'm confused as to why you're bringing tobacco and alcohol into a discussion about assault weapons.
But I'll play along, for one response only:
Tobacco: people kill themselves with tobacco. They don't kill anybody else, unless it's a freak incident in which a discarded butt causes a fire which kills other people. Tobacco is highly regulated and highly taxed, and the trend has been that tobacco use has gone down steadily over time. I don't see that downward trend slowing down or reversing anytime soon.
Alcohol: while some people do kill themselves with alcohol, I'm assuming that your "kills in the millions" comment is referring to drunk driving. "Kills in the millions" is an exaggeration, as the numbers I've seen from a quick browse of various web sites estmate alcohol related traffic deaths in the U.S. range from 16,000 to 45,000. That's a separate problem, one of personal responsibility. A complete ban on alcohol has been tried once, and failed poorly. I already addressed that on page two of this thread (my post of 12/17, 9:33am).
Also, I'm not talking about a complete ban on guns. That would cause more problems than it solves (refer to the post I just mentioned). I'm just questioning "is there a reasonable common ground? And if there is, do high capacity mags/clips, and assault weapons have a place in that reasonable common ground?"