I think you guys are letting the Sel hate cloud things a bit too much. After the Io thing, pretty much every character declares Nodoka terrible. Uta, who was harassed by pedophiles as a child, calls it the most disgusting thing she's ever seen. Imani, who was okay with alligators and Death Ball in her contests, immediately kicked her out. Ayane, probably the most lawful good member of the cast, mused that maybe Yumi was justified in beating her half to death. Even Otoha was disappointed. That's not a poor misunderstood genius, that's as in the wrong as a character can be.
I wouldn't see that scene as isolated from her fight with Futaba, but rather a further illustration of how fucked up her "everything would be fine if you looked at it from my perspective" mindset is. And given how explicitly she promised not to reveal Futaba's relationship earlier, and how she calls back to the lust novel thing when breaking her promise not to have sex with Akira, I'd say that Sel intended for Nodoka to be a massive self-serving hypocrite from the beginning.