I dig it!
My only suggestions are about the engraving. When barring eight notes, if it's a bar with groups of four I don't bar groups of 4 eight notes together, only groups of 2. It's confuses the eyes, especially young eyes, which you're targeting. Actually as often as I remember, I just group eights notes only in groups of two. Paradiddlez is an example.
The barring in Scrapin' Some Double Beat and Double Beat (first page) is terrible to read. You never really see this in real life either, so you wouldn't particularly be teaching anyone anything by them learning to read it. You've gotta bar those according to the beats man.
Other than that I think it's an absolutely great warm up pack.