Ship Guard = Yamato. Ice powers to freeze other ships, insane durability.
Diplomat = Vivi. Once the Straw Hats trigger the final war with the WG, they'll need someone to negotiate with other kingdoms.
Scout/Lookout = Carrot, who is fast, has great senses, and has amazing leaping ability. Was able to ambush Zoro in Zou.
Mobile Transport = Karoo, who is not only fast, but can actually climb up sheer rock walls.
Ninja/Beast Tamer = Tama.
Dragon = Momo. Dragons obviously have significant mythological and historical meaning in this story, Momo becoming a dragon will become more important as time goes on.
Bag of Holding: Caribou, as you said. (still not sure if Caribou will join or not)
Diplomat = Vivi. Once the Straw Hats trigger the final war with the WG, they'll need someone to negotiate with other kingdoms.
Scout/Lookout = Carrot, who is fast, has great senses, and has amazing leaping ability. Was able to ambush Zoro in Zou.
Mobile Transport = Karoo, who is not only fast, but can actually climb up sheer rock walls.
Ninja/Beast Tamer = Tama.
Dragon = Momo. Dragons obviously have significant mythological and historical meaning in this story, Momo becoming a dragon will become more important as time goes on.
Bag of Holding: Caribou, as you said. (still not sure if Caribou will join or not)