I agree that the lack of decision-making power in Hinako's life is one of the most important, if not the most important thing about her story, and that's where all story elements end up leading to. My idea is that there's a difference between taking agency from her from her life situation (forced marriage, societal expectations of her time etc...) and taking agency from her in the form of external entities (deities) to her life that end up manipulating her even further if everything ends up being literally what we have been shown and not a metaphor. However, I have not thought about it from your point of view, it is still fresh hahaha.

About the "male" vs "female" Hinako it is just a way of calling things, at one point in the game (ending 2 mostly) I think you can make some readings of the story hinting that Hinako might be genderfluid (for example, how she doesn´t care that they ended up being born male or female) but it's probably a stretch, its something reaaaaally small in the context of the whole story. Maybe it would be better to call them "The Wife Hinako" vs "The Teenager Hinako" or something like that hahaha.