I'd be willing to buy into some of the odd miracles there, but it still would mess up the entire time table - if He was doing those things and being noticed for them that early on in His life, wouldn't that have completely changed the context that the 4 canonized gospels are in?
Just the way that each person fits in to the "regular" gospels seems to contradict this.
Indeed.
The biggest contradiction, though, is the fact that the boy Jesus seems to struggle with sinfulness in this "gospel"; I mean, killing a guy who bumps into you isn't exactly nice, is it?