Well, this is a well-rehearsed topic but I'll add my usual two-penn'orth. No, I dont think you should ask people's permission to smoke in a pub(or not in Enfgland anyway). Pubs are places where people go to drink and smoke if they so wish. If you dont like that, lobby for change, but until the change happens dont be obnoxious. In peoples' houses, work places etc, of course you should ask.
   Folk clubs: simple, make your own rules if its in a private room, and ask people to stick to them. People won't object, if they do, throw them down the stairs.
    But telling people to stop smoking in a pub is like asking people to stop shagging in a brothel. You may not approve, but let's face it, that's what the place is for. Of course, in the fullness of time qnd with appropriate legislation, brothels may turn into place where people go to read the Guardian and eat tofu-burgers. But till then...
    I speak as a non-smoker, but when I go up to the Jolly Porters for a pint I know many people there have gone to enjoy their cigarettes. I have no intention of asking them to stop. When parliament decides otherwise, so be it. And there will still be exhaust belching cars driving past the pub. Smoke stinks, but not as much as hypocrisy.