99% NBA players can shoot and play good basketball otherwise they wouldn't be in the NBA.
Confidence = Scoring
Experience = Consistency
Shooting is more about confidence than technique. Once Lin raises his confidence to a comfortable level as a NBA superstar, his shooting will automatically get better and better as long as he keeps shooting in every game and in every practice.
For example, Steve Nash's first season with Dallas, his shooting was not good at all (FG%: 36.3%, 98~99). Tony Parker had some seasons with much worse shootings than Jeremy Lin's.
So far, Lin stands at 43.4% shooting percentage and 31% 3 poniters this season. Not bad at all and continues on improving. The thing is that McFool should help him build up even more confidence with more encouagement.