hello, other people

(with reasoning based on the character’s views/biases on gender)

Luffy - same regardless. Same face, same clothes - it's just Luffy with different pronouns.

Zoro - a bit different if we consider whether Kuina was gender swapped as well - regardless would result in Zoro wanting to be the ultimate swordsman (with a splash of proving a woman could do it) . Other than that, Zoro couldn't care less about someone's gender in canon, so stands to reason Zoro would dress, act, and be basically the same. (gets into a lot of fights with cook about being 'unladylike')

Nami - Probably still uses other's expectations of them to their advantage. Maybe projecting an image of a small, twink-ish man who needs rescuing to get people to let their guards down. Then outsmarting them and stealing all their stuff. Not very combat oriented, even as a man. Charms ladies and men to get what he wants.

Sanji - would fem Sanji (or Sanju) be a misogynist (genderswap version of him putting all woman on pedestals) or still be “every woman is a queen and all men are scum of the earth!” even as a woman?

and if so how would that relate to how she interacted with other members of the gender swapped crew? Like how could fem versions of Sanji and Zoro still fight and sanji give male nami preferential treatment

Usopp - pretty sure she'd be like Luffy in that not much would change as to how she presents herself as Usopp does not have any strong biases unless you count their "fairytale" stories. With damsels in distress and strong warriors. If Usopp were female she'd definitely put herself into the "great warrior" role regardless.