LeBron doesn't even have to posses a great 3pt shooting ability, but if he can master the midrange jumper beetween 16-20 feet, he'll be nearly impossible to defend -just like Tony. About the little nuances of the game that he needs to master to be great, well, he's just 22 fricken yrs old, and IMHO he's already in front of his development schedule.
Give him some more time & better teammates, i believe he'll figure it out sooner than later. One thing that can't be overlooked, he already has the mentality, leadership, and maturity of a champ, that's just fantastic for a guy his age IMHO.