Sorry to keep bringing up old things, but I had an idea for the mounts. It would essentially be building off of Mainyu's idea, though instead of calling them slaves, I thought there had to be a better name to call them. <<;
It could be a "First Mate" system, where essentially instead of a stables or bestiary, you would visit a "Shady Tavern" (that could be changed,
I'm not super familiar with One Piece so I don't know specific names of buildings) where you can essentially hire out a First Mate:
Since they're a separate person or companion, they would be able to assist you depending on how much it costs to buy their loyalty/services (such as how Katsuya heals and damages enemies, so maybe a Chopper First Mate would heal you and do minor damage). Basically the more expensive the First Mate, the more damage they do, the more perks, the longer they last (stamina), etc., just like how they are in SL.
In terms of travel points, maybe they would affect your "spirits" so that the more funny a character is, the more willingness you have to travel far. Or you can even just do away with the idea of adding travel points.
They would last "X" amount of terms depending on how large they are, or maybe proportionate to their stamina in the show. You can buy them a meal at the Shady Tavern once a day to replenish their strength as well.
Eh, just a random thought.