@Ares:
Not sure if this has been adressed (Still reading the thread lol), but I would like to point that this is wrong.
Supernovas were introduced in Sabaody because Oda's editors thougth the arc wasnt spicy enough and that he should add something more. That doesnt mean he didn't have them in mind: In fact, they are all characters that would make an impact in the New World and that Oda just decided to introduce earlier than expected.
So yes, expect important things from the rest of the SUpernovas: Not only Bonney or Drake (The 2 that will for sure get flashbacks since they already have an interesting story behinf them), others like Capone Bege will be geting their development.
If anything, you can use Sabaody to tell which supernovas will be more important, and it's pretty obvious that the 2 that are more important and are going to get more foccus are Kid and Law, since they were the ones who interacted with Luffy. I see Luffy fighting them just before the Blacbeard Pirates, since a triple captain fight would be awesome (LuffyvsLawvsKid) and Laws and Kids combined crews make just PERFECT match-ups for the rest of the Strawhats (Zoro vs Killer, Sanji vs Bepo, etc.)
Right from the first time Law got introduced I knew he was gonna be a friend of luffys, he won't be Luffy's enemy.
Then when Law, Kidd and Luffy came out to fight that scene sealed my speculation.
Law was talking to luffy with respect(probably respecting luffy for being a fellow "D") while at the same time he was telling Kidd he's gonna kill him. And yeah Kidd was arrogant to the two.