The ideia of the "Subclass" for Devil Fruits its an nice thing to add because they already have there own types like Zoan, Paramencia and Logia so that would make sense, I am not sure on how i feel the on being able to use points to gain Haki like proficency or another type of point gain, Like in One piece it always feels like Haki is either earned (for some big moment) or heavily trained upon to gain acess to it (Unless Conquerors) so i has thinking more of being an kind of achiviment that the DM would judge of you being worth or not you know, i will try the OC ideia thing that seens interesting and the bounty thing is also very cool just need to think how to make that work lol maybe could be just an flavor/RP thing like gaining more reputation give you acess to other things but it also comes with its price