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.
I think it might have been a character introduced to add depth to Sanji's backstory and motivations. But without more context, it's hard to say for sure.
Well, it could start with Naruto somehow coming across the world of One Piece. And he's immediately drawn to Sanji because of his cool fighting style and amazing cooking. Naruto might start following Sanji around, asking him to teach him how to cook some of his delicious dishes. And Sanji, being the chivalrous guy he is, might take Naruto under his wing.
Well, without more context about Sanji's story, it's difficult to determine exactly who the little girl is. It could be a childhood acquaintance of Sanji, or perhaps a character he meets during his adventures. Maybe she is someone related to a quest or a mystery in the story.
For many years, the prince of Qing liked Fan Ruoruo. In the movie, Crown Prince Li Hongcheng had always had feelings for Fan Ruoruo, and Fan Ruoruo was moved by his sincerity and companionship. In the end, she chose to marry Crown Prince Li Hongcheng.