Like I said, flying single pilot is over 8 times more likely to kill me than driving, but that's legal. If I'm injured from burns, or whatever, the health care costs are high. If my plane crashes into cars, houses, etc on the way down, then there's a big cost there. But I'm allowed.
Perhaps if smokers had a special smoker supplemental insurance in order to cover oral/lung cancers... though if people don't pay, you can't say "we don't treat you... you can go to our soylent green factory, or go die at home."
Really, it seems that it's all about mitigating societal expense. The other smoking illnesses and deaths are small amounts vs oral and lung cancers, so for simplicity sake, I will assume those fill in the gap for the 15% of these illnesses which are not related to smoking. Yearly national expense of lung, head and neck cancers are $15.7bn out of the $124.6bn spent on cancer care. Lost productivity is $40.5bn out of $134.8bn.
600k people die per year from cancer, and that costs $259.4bn total. Separate research values a human life at roughly $1.54mn, and a cancer death costs $432k, or 36% of a person's lifetime contribution to society. If we assume smokers are 11% to die from cancer, and other illnesses add what, about 4%? Assuming those illnesses have similar costs (non-trivial), so each smoker's lifetime insurance premium would be about $65k. That's basically $1000 per smoking year or $84 per month cost to society for each smoker. Add in administrative costs, and we're looking at a $100/month license to smoke.
People don't like separate taxes like this, so just add it as a product health tax that actually goes into a health-care bucket rather than general treasury. The US consumption for tobacco is 304bn cigarettes, 123bn pounds of smokeless (snuff, chew, pipe, etc), and 13.3bn cigars (small, medium & large). Cigars have a much lower rate of lung diseases, but otherwise have the same profile as cigarettes for head & neck cancers. Same with smokeless.
Roughly 22% of cancers, with adjustments as above, are from tobacco. That's $56.2bn expense (productivity and care) per year. Smokeless and cigars are about 30% of that cost. Add 13 cents to each cigarette, 7 cents to each pound, and 64 cents to each cigar. Blammo. Society's liability is covered. Hell, you could even have the tobacco companies directly fund an overflow insurance fund with this rather than nationalizing it. Active smokers don't get coverage under normal insurance for head, neck and lung cancers, but keep your receipt and file against the tobacco health fund.
Issues in restaurants, etc are mitigated by air circulation, or simply stating "we allow smoking." At that point, if you chose to expose yourself to the smell, too bad. As to workplaces, there may be limitations as to where some people CAN work, so I'm not sure about it from that perspective. Smoking in the workplace could be an issue, which could affect restaurants.