I remember he and Romo talking about how critical it was that Josh move his torso properly as well. The torso needs to follow the head, even when he cannot step into his throws or get the feet in the right spot, the head and torso are now connected and it makes every single throw better.
Also, you guys mentioned flicking the ball. To me Aaron Rogers is the prototype for that. Seems like at least half his throws are those tight little flicks and he ends up with his hand pointing toward the target, like playing darts. Josh has certainly developed that throw.