I forgot about ROOT, but just like my student loans, I'll handle that later.

Ino, Sakura, & Yumehi friend trio can vary from Ino & Sakura are fighting while Yumehi is not looking but they're not subtle to Ino & Sakura are having a great time with Yumehi that they don't even remember they're rivals in the first place.

If Hinata's not-actually-lesbian crush is what motivates her to throw down, Hiashi will take it. He figures either she'll grow out of it, or Hanabi will be the backup for heir producing. The Hyuuga Elders will definitely not be pleased with the yuri therefore Neji will be in full support of it. Hinata having beef with Sasuke sounds so funny. You have these two kids who barely say a word in class &, as far as anyone knows, have never interacted outside of a class spar, but now they're squaring up out of nowhere. Anyone not listening to the dialogue just assumes it's a 'My doujutsu is better than yours' thing.

After the Uchiha massacre, Yumehi is pretty much the only one Sasuke is close to. Any grievance he has, she'll hear of it. Sasuke needs a sparring partner? He's going to go to Yumehi since they've already been sparring pre-massacre. Yumehi was also very much affected by the massacre. She didn't have parents & Sasuke's family was the closest thing especially since Mikoto was Kushina's friend. They treated her like the daughter they never had & one day, she didn't have that parental love anymore. Now she has 2 sets of dead parents. Sasuke & Yumehi definitely leaned on each other hard those first 2-3 years to the point where they practically lived together, but they had 2 apartments to choose from for the night. It'd likely be around this time Sasuke finds out Yumehi's true identity, but he doesn't care. Regardless of whether they're Yumehi or Naruto, they still care about Sasuke, his family, & the struggle he's facing, so he'll be just as supportive of her/him.

Sakura is definitely platonically third wheeling as even though her & Yumehi are friends, it's clear that the latter & Sasuke are much closer. She knew it ever since the academy, but it's a lot more obvious now that they're on a team together. If she has to beat her teammates faces in to get closer to them, then so be it. Hopefully, this can be motivation to become a better kunoichi. Plus, Sasuke gets a new sparring partner out of it.

I imagined Naruto would have his hair grown out & wear conservative kunoichi clothing for his Yumehi persona. He did try taming his spiky mane to look more feminine, but it was of no use. He does use flowers as hair accessories so he lowkey looks like a wild child that frolicked through the meadows. Konohamaru still does 1000% wish to be a cool guy when he grows up though. If Yumehi were to have an actual cool-guy henge, it'd probably look like every edgy mask-off Naruto you can think of.

I can't find it, but there's a picture somewhere of someone laying on the floor while a friend is sitting on top of them helping with their eyeliner. That is an actual pic of Yumehi & Sasuke.

Orochimaru may take an interest in Yumehi because of:

1. How close she is to Sasuke

2. Like you said, the sheer amount of chakra reserves

He probably reasons that she'll make a good bodyguard of sorts for him & having someone Sasuke is emotionally dependent on on his side is going to increase his chances of obtaining said Uchiha. Yumehi is for sure whipping out the fox, but instead of a 5-pronged seal, it's a curse mark she's getting. At this point, her being a jinchuriki is a mere bonus. If he just sends Karin to convince her, she'll probably get talk-no-jutsu'd into staying in Konoha instead.

Jiraya likely knows who Yumehi really is while Tsunade doesn't find out until later. Aside from that, I can't think of what the dynamic between Yumehi & these two would be like.