im just excited about this project and im sure everybody in the community will fall in love with it, it has so much effort and love.
i think that some important things are:
making the player to feel completly free (giving, for example, the choice to leave the hidden village and become a rogue shinobi) but making the choices as realistic as possible, with real consequences (for example, the chance that your character appear in the bingo book if you become a deserter).
the chance to become "powerful" by different ways, by becoming a asshole who only cares about wealth like Kakuzu, by becoming a famous healer like Tsunade, or a heartless elite ANBU
i would like to see mechanics allowing people to become part of somethig, maybe the option to form a clan (or a group, like akatsuki) with players (separated from the hiden villages system) and go to war with other clans.
another thing that i would like to see is -maybe too ambitious- but at a certain point having the opportunity to create your own jutsus and become a legend, like Orochimaru, Minato, Tobirama, etc. did
but that's just some things that would make the game awsome! nice job and good luck!
(sorry if i expressed myself wrongly, english is not my first lenguage)