DByrd and LaFell are two of the most talented receivers in the SEC (and that Tolliver cat ain't no slouch either.) In my observation, I find that Lee has less problems throwing the deep crosses and slants much more accuracy than the quick throws. He seems like he's the kind of guy that can get the deep ball where it needs to be. Also, the kid throws a crappy screen pass. And it certainly doesn't help when you throw screens and quick outs on first down every freakin series. So far to me at least, it looks like he gets his rythm throwing deeper balls and then coming to the short stuff, which is pretty much the opposite of every other qb out there. But it seems to work for him.
If the O-Line had shown up to protect him, he might have been able to. The screens and quick-outs loosen up the pass rush and allow for the slower-developing long bomb. You can't just throw long every time when they are loading up and bringing 6-8 rushers against an uninspired O-Line. On his talents and weaknesses, I somewhat agree with you. The quick-passing game takes a lot of timing and chemistry and he just hasn't developed enough yet to be lights-out with it. He'll get there.