I think the lowest hanging fruit at this point is fixing his footwork. I don't have the slightest idea as to how fixable it is at this point, but they're gonna have to try. Proper footwork will definitely add more zip to his ball and improve his timing and accuracy. This should be priority numero uno.
You'd think a No. 1 draft pick wouldn't come with such piss poor fundamentals, but it is what it is.