Good to see another comment from you my man!
1. I'm writing Bianca mostly around the part where her Dad shows up and tried to convince her to come home, in my story she's just starting out as a Trainer but lacks the confidence to leave home.
The MC finds Victini and figures that she could make Bianca feel Victorious and give her the push she needs to break away from her parents and leave on her adventure!
2. Reshiram I'm matching to Hilda, the only real reason for this is that her name was "White" in the Japanese pre-release content, she is also an MC from Black and White so matching her to one of the main legends makes sense to me, Zekrom I had going to Iris because of the Dragon Typing.
Kyurem is actually going to Anthea and Concordia, the two Plasma Members who looked after N when he was a child.
I have no current plan for Rosa, but your suggestion of Keldeo seems good.
3. Part 1 will be Mythicals + Swords, Part 2 will be Main Legends + Genies
I broke it up that way because the Swords need to go with Keldeo
Cucking Nate in the Ferris Wheel, I can work with that, I already had one Ferris Wheel scene planned, but I can make another one happen!
The Undella scene was the return of Cynthia if I remember right, I'm doing that for sure!