Perhaps something for both F2P and P2W players. Have level gaps for corresponding events taking place. For those level 30 and below can have nice events that'll help them get items and coupons to catch up and increase their strength, while also pitching them a decently strong ninja.

Players above 30 can have slightly more benefits, but not that above lower levels to they don't feel cheated.
This can be more focused around ninja fragments and ninjas they should be able to get.

And for the sake of a long strength, lower levels can be given the Chunin Medal, like it's given when they first start. And higher levels can be given and bare with me very limited Jounin medal as a trail.
It can of course be given without the coupons and naruto nine-tail fragment that comes with it.

Honestly at this point, I think rebate events and other spending events should only be shown for people who have spent money on the game. Aka Jounin Medals. They shouldn't make it public, meaning they have more room to open up more and creative events for those who don't have the money to enjoy this game.

Being pessimistic doesn't help a lot my d o o d

Hm, that seems like a good idea.

Hopefully you can put them to good use.