To the bit about Bernadetta's genius being recognized by her family--
It's not fully come up yet, because she hasn't officially claimed the right to take over as head of her House. But she did declare her intentions during the string of chapters focused on her story, when Seraphina and the foreign prince together boosted her self-worth & confidence enough to stand and take what's hers. And her abilities were informally recognized by her father at that time, though it's not concluded yet and we'll have to rejoin her story to see what happens.
I do think this was somewhat necessary, because it's another facet of Bernadetta's life within her House and it adds another layer to what she's had to put up with, but from outside her personal perspective. We see that she was correct all along--Aini is A Problem, but nearly everyone around her is simply charmed (Magic Charm'd?) by her beauty and demeanor and personality.
The Brother here gives us a perspective akin to *Orva's on how Aini's fucking things up for people, while also further fleshing out Bernadetta's specific relationship with both the Saintess Apprentice and her own family. She's redeemed as the Brother realizes that she was always a genius, and that he has crippled his chances of inheriting his House due to his own negligence and complacency.
There's a chance he turns the corner and comes out a slightly better person. We saw in his early childhood that he was effectively poisoned by his mother, who seeks more power and control within that House. He's been conditioned and manipulated, but isn't wholly lost; he can see here that he's been an idiot, and blind to what's really going on around him, and has resolved to try and make up for his failings in a constructive manner.
So I think he'll be replaced by his sister, and won't get what he thought he was entitled to. But he'll probably come out okay-ish, and not be subjected to "Punishment Unending" as Bernadetta takes over. He's still her brother, after all, and she's one to use Useful Things, of which he could end up being one, now that he's gotten the rose-tinted glasses off and been made aware as to what's really going on.
You are correct - he's an annoying character, and I think we as readers are meant to dislike him, but to feel some sympathy for how he's gotten to where he has. The fact he actually acknowledged that he's fucked up, means he has potential to get back on the right path. Hopefully with some chastisement and not blanket forgiveness, but allowed the opportunity to work hard and gain some measure of respect again.
