@Airflow101:
Who the fuck cares?
This.
Honestly I don't see what the big deal is, there aren't THAT many smoking characters, and it's not really out of place in the manga like smoking is in real life.
For Smoker it fits because it's his name/his fruit is smoke. If Smoker didn't smoke then it would be kinda dumb.
For Crocodile it fits the image he projects. The sophisticated middle aged man. Though I don't recall him with a glass of scotch in his hand, the other big stereotype is the cigar. He's just got that look to him.
Same with Capone, he's got the mafioso/godfather thing going on.
I'm blanking out on what Wiper was smoking, wasn't he doing like opium or something? I really need to read Skypiea again and pay attention.
As for Paulie, honestly I would use the excuse he thinks it makes him look cool XD Even though it was only mentioned, he seemed to have a bigger affinity for beer then he did for smoking, never really explains or shows why he does. Maybe it was just a design trait Oda added to protray a gruff, edgey, hard labor working man. Like a roughneck, especially back in the day, to them cigars and beer were great luxuries in life.
As for Sanji I think it's just a personality thing. Sanji has a classy look to him, which cigarette smoking also fits that sterotype.