I think having a donation system with account rewards set's a dangerous precedent, it opens up exclusive perks to those who are willing to pay. I don't think donation rewards should be anything account wise. Something that was mentioned like maybe vote on a season change in dunby would be a cool idea, or maybe the statue of the player in game or something. Maybe even a highscores or donations etc.
I think setting up a patreon would be a good idea, sans the legal ramifications that may come even though it's donation based. It would allow the people who can afford a monthly payment of say $ 5 dollars to support the creators and their efforts.
But please avoid setting up paying for fashion or cosmetics!
Heck set up a Twitch channel and I'll give you my twitch prime sub! That's a cool $2.50 in your pocket each month