Toge Inumaki is important too. His special cursed speech ability makes him stand out. Also, the principal of the school, Masamichi Yaga, is likely to be important as he is in a position of authority and has an influence on Gojo and the other students. There could be other characters like the members of different clans that also play roles in the complex web of the story.
Well, in such a fanfiction, there could be various hints. Maybe Zoro's behavior might be more in line with typical female characteristics described in that specific fictional world, like being more empathetic or having different social interactions compared to the original male - character version. But it really depends on how the author has crafted the story.