Garp is going to trash Luffy, but I think that during that combat the old man will let the key slip so Ace can be freed. I mean, fighting Garp Luffy has more of a chance to leave alive than fighting Sengoku anyways, so I assume that Garp is half-helping Luffy, half-doing his work as a vice admiral. He's been doing that for a while I think.
By the way, there was another rokushiki zoan-fruit user fighting Luffy during the massive combat in Marinefort right? Those rokushiki users sure love their zoans.
Do you think all of them get to the archipielago or that we are going to have them rejoin the crew slowly? I rather have them all at once to be honest since we got enough provisional crews during the Impel Down arc and right now.
You think Luffy's bounty is getting increased after breaking into ID, freeing Ace and hitting one of the favored families? It would make sense I think.