I identify with Rin on several levels, she reminds me a lot about myself when I was a teenager. And yeah, she's a true bro. You can't really expect her to an adult bro cause well, she's a teenager. But even when she messes up, she's trying her best.
Oh, that phone thing makes sense. But then again, Rin is probably the one that knows more about Akira banging people other than Ayane and Maya. And not one of these are wizards. So, I don't think she'd conclude it's because she's not a kid. In fact, if you're a good homie it's kind of clear (from her perspective) that Akira didn't push for Rin because she made it clear that Otoha was her priority and, again, Akira probably is the most healthy with Rin out of everyone else.
He did push a couple of times though. She just never gave him an opening. It's just not his mo to keep pushing when there's clear resistance.
It's funny to think that Akira's class is fully made of people the school doesn't want to deal with

Other than Makoto I guess. Also, I do wonder, since the city keeps moving, what is happening with the rest of the school? Do the other classes change? Does the school itself change? Do the people we don't see become stuck as well? Or it's just when we start seeing them that they get stuck?
Edit: oh, something about the Rin event, why exactly does Rin get mad? Cause I mean, technically, it's Niki that Akira betrayed there. Otoha's the one that betrayed Rin. Is she mad about Akira involving Otoha in her life again in a bad and roundabout way? Is she mad because instead of asking her for nudes he went to Otoha? Is she mad because he kind of used her in order to get closer to Otoha/corrupt her? I don't really know.
I also wonder if she's gonna talk to Otoha about it, cause in that case she has A LOT of cause to be pissed at her. "Hey, my name is Otoha, I cheat on my girlfriend, hide that from her, and then after breaking up with her, I use her nude pictures to get a picture of the girl I cheated on her with". Such a trashy person.