Must keep both swearing and smoking, while to an outsider they might just seem like irrelevant window dressing that only obsessives would care about maintaining, they are central clues to his character. They emphasize his jaded, salty, reckless, uncaring, and unhealthy nature (Especially when we meet him). Particularly the abuse of Shera with expletives sticks out and shows how his character is when we first encounter him, and further dramatizes the way he changes later on. The smoking is more like, damn we've seen a lot of fucked up characters up til this point in the game, but even Don Corneo didn't smoke. In classic FF fashion, Cid is an obsessed SPACE pilot, but his characterization is more of the traditional boat pilot...he's a pirate ; )