The problem is, he has writen so much about it already (look up Enters deviantart. He wrote the "first book" and also gave a general outline of his world and ideas) and it just adds up to nothing good.
Your idea of a kid learning also about responsibilities as an adult is something done a million times, but also the most logical to do.
But not enter.
In enters world, the kids are in charge and everything is good with the world.
It is like KND, if Nigel had become some sort of Big Brother figure and adults had been reduced to the role Timmy Turner and others have.
Only the adults are not supposed to get "too many" breaks in the show.
Also, hsi diea of writing humor is assanine. Essentially the kids are okay to be slightly mean spirited, but adults can't be mean spirited towards kids at all, not even in retaliation for the kids screwing up or exploiting power and there is meant to be a lot of weird "heartwarming" family moments at the same time that feel utterly forced.
It's like Friendship is Magic had been mixed up with Teen Titans Go, Fairly Oddparents and the Brady Bunch.