I'm with you on all this, which is very close to what I've got him doing, with the exception of the burpee/squat thrust. I like the idea of including that as an explosive movement.
I don't think it's a case of too much time at soccer so much as playing only soccer. From what I've seen, kids who just play soccer end up with tight (but strong) hip flexors and hamstrings.
I was thinking that I'd like him to focus on a higher number of reps and more time at each movement, with the idea that he'd be able to really groove that main movement. I guess the reasoning was kind of keeping things simple and avoiding the distractions that might come with multiple big movements, at least at first. Thanks for the input though -- you've got me thinking, which was kind of the point, right?