Normally these kinds of promotions are a turn off to me, but I can see you're actually trying to add value to this community, a really noble intention for sure.
As far as the balance between payout percentage, I'd say you're really close if not spot on to what I would think is fair. You would want to incentivize good posts to a large degree, and also reward the curators who work to find those posts to a lesser degree. The 25% for just being a curator seems like it could backfire though.
We'll see how it starts off and if a hardfork in the project is required after a while. ;)
:) being a curator is hard work. right now I do it for nothing, and it is painful when you find the level of issues that are on here that most folks do not see.
And I will continue to do, even if I am not picked because it is how folks are found :)