The use of Wendigo in fiction isn't inherently disrespectful. It largely depends on how it's portrayed and whether it aligns with the cultural background and values associated with it. If handled carelessly, it could raise eyebrows, but with caution and understanding, it can be okay.
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.
It's hard to pinpoint exactly where Gojo is at any given time in the manga. His whereabouts change as the story progresses and different scenarios unfold. It could be in a supernatural realm, a mission site, or interacting with other characters.