Yes. The conflicts between Sanji and Luffy in the manga often stem from complex circumstances and character developments that drive the narrative forward.
As of now, Sanji is very much alive in the One Piece manga. The story keeps unfolding with him as a vital part of the plot. The author hasn't written his death yet.
For Nami, her intelligence and cunning are key. She could use her smarts to get Sanji out of trouble in the fanfiction. Also, her love for money and treasure can add an interesting dynamic. For example, she might convince Sanji to go on a dangerous adventure in search of a valuable item, promising him new ingredients for his kitchen.
Fanfics about Sanji can also be about his dreams and aspirations. In the original story, we know he has certain goals related to the All Blue. A fanfic could expand on this, perhaps he discovers a hidden route to the All Blue but has to overcome various obstacles, like dealing with a rival chef who also wants to claim the All Blue for himself, or facing a sea monster that guards the entrance to this mythical place.
Well, without more context, it's difficult to say precisely. It could be that Sanji is a victim in this ghost story, constantly haunted by a malevolent spirit. Maybe the story is set in a small, isolated town where Sanji discovers some dark secrets related to the ghosts that are terrorizing the place.