First of all other would suck immediately. Second of all I'd make it less about brawls and more about adventure and go back to the simplistic art style from the past where the background wasn't so consumed with detail that it distracted from good shoto of the characres in motion as well as I would stop naming every attack and use more choreography in the fights kinda like sanji vs Jin or most other east blue fights. I would have the plot be undertonedone by different types of human conflict that appear a lot less regularly like man vs self or man vs lack of God or man vs nature. I would make all the dreams the straw hats have progress as much as their fighting abilities i.e. Nami would constantly be looking for parts of different maps on different islands and chopper would go collect new and exotic sampleso every chance he got and sanjo would always ask around about east blue. I would have constant challenge on Luffy as character worthy of being the captain of one of the best crews ever assembled.
Also a bounty hunter monkey riding a turtle with a squid would be a thing.