Chesedname: i think that oomis is tring to tell u that he is not talking about laws, legally, we are talking about Yiddishkeit, and maners (wich go together), and i agree to that.
And about the Yeshivos; u seem to have not gone to the yishivos which “allow” smoking (you may be a female), so i will tell u that there is no yeshiva that i know about that allows smoking. The point that was said about being strict is also not true. In mesivtas (high school) again every yeshiva i know about, is strict about it. However you will find that in Beis Medresh (after 12th grade) there are places that are not strict about it. This is understandable, since they are already 18 years old. So (chesedname) if u want to look at it in a leagal way – they are 18 – and in a religious way, i don’t want to get into an hashkafic talk, but b’kitzur this is what they are doing at this age (the age that usually one has his commen sence) (and other reasons combined, about having an outlet, not doing worse things..), so they wont be so strict on them.