I really love this! It's a pleasure to use. I've wanted to make something similar for our educational toolkit Gamefroot for years but we've never got around to it - as you know there's lots of moving parts!
But now that we have some inspiration (you beauty) we are porting this interface and all the variables into make.gamefroot.com. It's not currently visible or ready to show off but I just wanted to let you know that your work is inspirational and that we will be engaging the next generation of game designer with your thinking and our thinking combined.
I'd love to chat more about this if you ever have a spare moment :)