Now I see where you are coming from about the AU. This is quite a big AU. I would have actually taken Garp and contacted Rayleigh and got them to Banaro Island. Since Ace and Teach fought there a week after Luffy sailed out from water 7.
Your portrayal of Rayleigh is weird. He already knows most stuff to do with the yami yami no mi. Your making him act shocked over info that he’s been shown to know already.