User blog:Pandawarrior/What if Luffy and the SHs had joined the Whitebeard Pirates?

When Ace and Luffy met each other in Alabasta, Ace invited Luffy to join him in the Whitebeard Pirates. So I was wondering, how would the story have panned out IF Luffy and the rest of the Straw Hats joined the Whitebeard Pirates?

Would the war have happened?

Would Luffy learn Gear Second?

Would Robin have joined them?

etc.