First of all, I love how you always find a way to get Emira into the discussion 🤣

Yeah I think she would. To be honest I believe Emira never really liked Boscha as Amity's friend. Say that she realized Odalia was constantly making comparison between both families and also how Willow got treated to favor a relationship with Boscha, so yeah at the time she would dislike her.

But I think now Emira is quite conscious Amity can manage her own relationships alone. I don't particularly believe Amity would resume some friendship with her, only casual acquaintances that met up in collective events. It would surprise her, that's it, maybe would ask Amity if she feels comfy with Boscha's presence but nothing else. She is cautious, not a controlling freak fhjahdjd

JEJEJEJE it is messy.
As many people know I think of vinira as a VERY slowburn and they don't date until years later, maybe even after the time skip.
But long story short: Emira confesses first because she's a flirt but also because Viney is probably the first real crush she ever had and she tries to do better.
She gets rejected because Viney's first impression of Emira is... bad. For her Emira is still this pretentious jerk girl who makes jokes and takes nothing seriously.
After that rejection Emira changes A LOT (at this point Amity is missing, and maybe she didn't change, she just started to grew older) so this new version of her makes Viney confused and of course, protective, and of course, other feelings start to bloom once she gets to know big sister Blight.
It is a big etcetera of things that happen between them in these months between labyrinth runners and Belos' defeat, they only get to work in their feelings after the final (I like to think they become very close working together at the healing track), but yes, that's basically how it goes.
A note to add: Viney also gets rejected but not because Emira doesn't like her jfjsjf, Emira is way too fragile and is afraid to hurt her because of that, also Edric was all wound up and she didn’t had mind for anything more than her brother 😭

Damn, THAT'S a question
Well since it is canon they used to be childhood friends, I always have envisioned them as a opposites attract thing and as a team that work together but it is pretty unbalanced. I believe Odalia saw Alador's potential as an inventor and just got closer to him on her favor, since Odalia's character is pretty much based in her desire to escalate positions and taking taking advantages of it. She is clear in that.
As many people know I always have issues describing Alador's intentions and goals. He seems pretty uninterested in anything but his work and I believe this influenced Odalia taking control of everything (even his own name and magic). So yes I believe they are a very disbalanced capitalist couple that works because they know their "part of the deal" (lol) but also as a ticking bomb that would've exploded sooner or later.

rubbing my hands like a fly
look. I GENUINELY BELIEVE Amity would forgive her, and she kinda does in the FTF episode.
Amity is a very selfless and caring character who even tried to appeal to her mom's good side when the whole day of unity thing happened, and Odalia has been the only character she completely cut ties with. Amity knows Boscha is a highly troubled child with anger issues and probably the same obsession with winning, being the best and keep everything in control as she used to be before Luz, so she get her, not justify her, but she knows Boscha needs time and real connections in her life.
Amity is a character that always gives a second chance and won't judge you at first glance if she sees good in you (Alador, Hunter, Lilith, Luz, even the Collector), so having a beef with Boscha would be very OOC of her. I think Amity would encourage Boscha to be a better person and care for those who always stood by their side, but I don't see Ams hanging out with her or the grudgby team anymore. Maybe they chat sometimes to each other about unserious things, and every once in a while Boscha still tries to surprise her with her progress or invites her to play some friendly match with them, and Amity would agree for pure courtesy and the sake of sportsmanship and fun. I don't see Boscha apologizing but being less of a jerk with everyone, her kindness is only directed to herself and her teammates only, and Amity is a constant reminder she can be a better leader everyday.
Also, I believe Amity is the one who invites her to Luz's quinceañera party, and she would show up because, I mean, the human saved her team, is the least she can do, to show some grattitude (giggles).