Sorry about the delay in replying! This thread has got me running around trying to reply in an intelligent way to every comment....
I agree that it is big problem of where to draw the line if we applied laws as mere guidelines... in that case why bother having them. However, I do think that after the law is applied then we should be flexible in the allocation of punishment or penalty (well, maybe not for parking fines, but I think you know what I mean!).
I'm a non-smoker, but I would hesitate to ban them completely in public places (if by that you mean outdoors). Indoors, I'm against smoking, but outdoors I don't mind so much. It's funny that you mention these smoking rooms, I recently was at a concert hall and backstage there was one almost exactly has you described, a glass box with a huge exhaust fan... seemed like not fun, I'd rather go outside!
I think there is scope for being able to smoke outdoors of that's your thing, but it needs to be in a way that does not impact anyone that chooses not to smoke. Public spaces in urban areas should absolutely be non smoking zones.