This school sounds like some sort of weird Kafkaesque punishment for kids. Everyone is trying to game it: kids who don't want to write essays, administrators who don't want kids to fail. Teachers who want kids to both learn stuff and pass.

Motivate the kids. Show them stuff about the world, and show them how to find out things for themselves. If you're going to test them, do it in a way that doesn't destroy all enjoyment of the subject. Try to get the kids to want to keep learning after they leave you.