This is the logical conclusion when you socialize healthcare. If you’re pro NHS / single payer, you *must* support this. As well as banning drugs, sugar, extreme sports, unprotected sex, and other high risk behavior. Anything short of this just doesn’t make sense.
You are wrong. The swingeing taxes on cigarettes already cover the healthcare costs and the smokers die early saving even more money.
I thought cancer care tended to be pretty expensive. Not sure that your math is so clear cut.