I feel like...with the exception of his father, Sanji is too harsh on the rest of his family.

I mean, yeah, his siblings picked on him. When he was, like, 5. He hasn't really spoken to them since then, so it's hard to tell if they're all still the same assholes they were as little kids even.

His dad almost feels like a false antagonist. I feel like, at some moment when their dad displays weakness, one of the siblings is going to take him out and take over.