First, I clearly remember Jay Barker being adverse to the long ball in that 1992 championship run. He threw for 1614 yards, 7 TDs, and 6.6 yards per attempt. That team won a championship. Blake had 250 yards, and an average of 7.6. Also, he threw a ball around 60 yards in the air and it could have been an easy TD if not for a drop. He's capable of making the throws (not on par with some QBs, but to the extent that he can hit a guy way downfield), he did make a couple of the throws, but I do question how dire the need is to do it much. If you know he can do it, which he can, you still have to cover the deep man.
The flip side, which doesn't seem to be mentioned much is what Blake can open up with his running game. You have to worry about what he can do with his legs, which can then open up other things. Rather than worrying about opening up the offense with the deep pass, I'd worry more about using Sims speed to Alabama's advantage. He ran for 42 yards and evaded a few sacks, but he can do more than that. His legs can open up things like some quarterback's arms can.
I think if Blake remains the guy, the offense needs to adapt to him vs. trying to get Blake to adapt to the offense. I don't think anyone can watch that tape and conclude Blake can't lead a team to title contention, not after seeing what Nick Marshall did, or Pat White did for example.