Wow, that's the ONE aspect I wouldn't be worried about. Kid is definitely a pure shooter. You would expect his numbers to get better IF he's the real deal, which I think he is. So just like he embraced playing defense when Cal challenged him, I can see him working to improve, learning how to get open off screens, etc. Almost 40% from 3 as a freshman is nothing to sneeze at.
Lou Will is my dude, but Monk is a better shooter. When I watch Monk play I see a shorter but slightly more athletic Rip Hamilton. That kid develops Rip's mid-range jumper, and it's OVER.