“The Ghostbusters AREN'T the Ghostbusters if they don't smoke.”
You're kidding, right? Smoking does not define a character. As a matter of fact, I can only think of ONE character from a movie that would be weird if he weren't smoking all the time…Silent Freaking Bob. Everyone else is negotiable. Whether or not they smoke should be a non-issue…unless they're planning on doing whole stories about it, that is.
Personally, I always thought Ghostbusters was about busting ghosts, not whether or not they smoked Camels or…heh…Winstons. Besides, I always thought the reason they smoked in the movie was because they all really DID. If you can write off cigarettes to production cost, why wouldn't you? If they're smokers, then they're smokers…but aren't there better things to demand from the people that are working very hard to bring us a product that we'll enjoy?