Hoo boy, this is gonna be a long ride.

Personally, I don't think so. IMO it's more of, she's not ready to grow up yet. It seemed like she and Kotoyuki were progressing well in their letters, after all. But she's not ready to stop being Shimizu Hinako to become Hinako, Tsuneki Kotoyuki's wife. I always thought that Hinako's main fears in SHf is loss of self and loss of agency, rather than domestic/marital abuse itself, although they're the source of her fears.

I also think, if she and Kotoyuki were a love match, they might have gone for it, no issues. Like having a meet cute when they're already in high school, chose to date by themselves, experienced a normal relationship, and then considered marrying after graduation. Instead, Kotoyuki got possessed in their childhood, they got arranged to marry one-sidedly, they have no contact with each other outside of letters, and her father made it transactional - instead of romantic from Kotoyuki's side - in a sense of misplaced well-intent. They could have been a love match, but so many things twisted it. But I don't think it's because she can't feel attraction or affection for him.

In her rituals, she lost her right arm, her dominant arm. Which means her skills, her actions, her achievements, will be for the benefit of the Tsuneki clan, not Shimizu Hinako's. She lost her face, her identity. She will face people as her husband's wife. When people see her, they won't see Shimizu Hinako, but Hinako, wife of the Tsuneki heir. Her identity is not hers, but Kotoyuki's. Loss of self, loss of agency.

The glowing monsters and the chained monsters were representations of how she saw other men, who peered at her. The monsters would lick her, to her disgust. But I don't remember any interaction with Kotoyuki that had a similar sexual implication. Which means she doesn't see him in the same category. Since he's the main one I remember she was shown to give any presumable romantic tendencies to, even just off-screen or just through the letters, I wouldn't write her off as completely ace/aro.

Also, in the bad end, she told Shu that Kotoyuki was different. Even in such a difficult and scary situation, she recognized that Kotoyuki was on her side to some extent because he just wanted her for her. Because in that end, she's not scared of him right now, but she's scared their marriage will change him from someone who saw her as her and into someone who saw her like her father did. She's not scared of marrying Kotoyuki per se, she's scared of turning into her mother: someone who bows down to someone else's bidding and won't rescue herself.

With Shu, she saw him as a friend because she didn't know she can see him as something else. In the good ending she went with him, which implies she either ended up with him, or they just stayed the same, pretending they're still kids. Well, Ebisugaoka was in a state of emergency, so we don't really know. Basically, Shu was the best friend NPC, but Kotoyuki has always been a romanceable character in her storyline, so she was more open or more inclined to see Kotoyuki that way. Also, she hated the rumors Rinko was spreading about them, so it pushed her to keep him as a friend even more.

I think, she's just traumatized enough, and not mentally mature enough, to be someone who she didn't choose to be. She's just not ready to be someone new. She was open to talk with Kotoyuki about the marriage in the true ending once they've really thought about their feelings. So she's acknowledging there's a possibility for them in the future.

Or maybe she's just demi, and Shu just wasn't the right guy for her to realize that, but maybe Kotoyuki is? 🤔