I mean, how much of these "good actions" Nodaka does is because of "empathy" and how much of it is because she wants to progress the stories of the characters? Like, I don't know if this is a mischaracterization because I don't really pay attention to her scenes, but it seems like she finds people the most interesting when they're being truest to themselves, good or bad. It also fits in the context of her writing her story about everyone in the class. And honestly, there's kinda no point in bringing up the outcomes when we're considering the intentionality of the character.
For example, you can interpret the scene with Yumi as her getting revenge for Futaba, which certainly was an element, but also an exploration of Yumi's character. Yumi doesn't have a single romantic scene with Sensei, but Nodaka wanted to probe her and confirm if Yumi actually does have feelings for him. That's why Nodoka doesn't do anything with Sensei and just comments on how she didn't expect that if you got the route where Yumi just leaves instead of masturbating to prevent the blowjob. Furthermore, Nodoka doesn't follow through with the blackmail, showing that she was always more interested in Yumi's character and forcing her to progress rather than getting revenge for a friend.
Also, on Kirin, I didn't see the Ayane scene so I can't comment on that, but yes, she's a confused hormonal teen harboring an inferiority complex which she copes with by pretending she doesn't care about anything except sex. And her entire arc is breaking down that act she puts up - in fact, I think the thing with Miku supports this point because you can see how uncomfortable she was. Doesn't help that there's a thirty year old man that's literally her teacher in the room that keeps goading her on and enabling her to keep going down the destructive path.
So yes, Kirin makes shitty choices, but that's mostly because she doesn't understand herself. Nodoka completely understands herself, and every "bad" thing she does is completely justified to her. Kirin is hypocritical, Nodoka is not.
But again, they're all kids and their brains haven't even really developed so I don't blame them. Maybe be a bit more concerned about the grown ass dude who understands how he might accidentally r*pe underage girls but still decides to go on dates and spend time alone with them. It is seen through his own decision-making that r*ping kids is less important to him than his personal satisfaction. If that's not a monster, I don't know what is.
