@King:
Heart Pirates probably won't be coming though. They have no obligation to face Big Mom, and Law kinda needs a rest from the story (not to mention that the Heart Pirates are still wounded). If anything, they need someone to watch over Zou.
And Jack's being foreshadowed to arrive before Luffy departs anyway. Jack himself is still after Raizou.
Luffy will go alone, or at least before everyone else. The whole point of him going alone is to prevent a major war. After all, why introduce that possibility if it ends up not happening?
My main problem with leaving the Heart crew back on Zou is mostly because of how badly things went over the last time when the only member they were missing was their captain, and even with Law there it's hard for me to think of the situation improving by much. I realize I've been overlooking the addition of the remaining SH and the samurai's helping out, so I've changed my mind about my earlier statements.
About Jack. Didn't Wanda mention in 806 that that the Navy may have him in custody? I guess I was thinking that they could hold onto him for longer, but with two failures under his belt, I guess it's not going to be long before he breaks out and starts coming at them without any of the patience that let the first battle stretch out for as long as it did. It bugs me that he'd be going back to Zou when days of fruitless interrogations revealed the lack of Raizou there, but he's probably a spiteful guy.
We'll just have to wait and see if Luffy does get to go off on his own. I still think it'd take more convincing or some additional naunce before Pekoms will agree to it, but that's if something else doesn't happen to change up their options first.
@RomanceDawn:
With Nami, I don't doubt she could single handedly take care of any major gas clouds. I've long since held the idea that her abilities are almost too good. She wouldn't be able to neutralize the gas but dispersing it out over the open ocean would certainly help in supporting the physical fighters.
Caesar being with Big Mom makes me thing that Jack may be given a new objective to retrieve him.
facepalm Ack, I forgot all about Nami's AOE weather attacks. Also, forgot about the rest of the SH's possible contributions like Franky's mecha and Usopp's plants. Those would definitely be invaluable to a counter attack against Jack and the Beast pirates, assuming they plan on simply gassing everyone and picking them off again.
With all this new info about Sanji's family, I think I'm just getting impatient with Zou and want it to be over with so I've been forgetting a lot of things.
Need to remember that the samurai have to do something about how their rendezvous indirectly caused the Mink's suffering, the secret behind their mission, that Zou may have some potential nuggets from the past like FI's Joyboy promise (heck, i'd be satisfied with just the story behind this gigantic elephant with unbelievable long legs that's lived for a thousand or so years), and whether the schism between Inurashi and Nekomamushi have to do with anything significant.