KiddieToysReview
I Love YTtalk
Personally I think a fee would make more sense. You have to have at least 20 videos, and then you submit an application for a $100 fee, if your approved you can be shown on YT kids.
Even better: 30 videos, 3 months active, 1M+ channel views, 1k+ subscribers, $250 fee. No problem meeting those criteria for those who want to seriously work in the space and are committed. That would still make it the cheapest business ever to start. Even a crummy old food van will set you back $30k, or a centre-aisle stall in a shopping centre at least $15k, so starting a Yt kids channel business for less than $1k is fantastic.