3 Episodes in my quick thoughts
The casting has been good so far, my favs are Nami & Buggy. Emily Rudd IS Nami and knows how to portray the underlying emotions Nami is dealing with. It's great seeing subtly her react to stuff we know affect her(due to reading the manga). Jeff Ward as Buggy just steals the show, this dude really is charismatic AF and probably will be a fan fav for the non One Piece fandom. The one horrible casting is Beckman, like who tf is that guy LMAO. Beckman fans in the dirt
Aside from that is campy and goofy, but that's pretty much what One Piece is. The best you could do is recreate that but also make sure to highlight the emotional moments.