I think what you missed in your analysis was a change in coaching philosophy between 2011 and 2012. On the one hand, that plays to your points about Miller carrying the ball more, with a decided emphasis on him being the featured player. On the other hand (Bollman troll alert), the SCHEME of last year was much more integrated, even when Miller was making mistakes, than before, virtually guaranteeing better over-all output.
The training wheels are off this year, with knowledgeable players working within a consistent scheme. Regardless of the "pro ratings" of the line (which, really, who cares? this is college, not pro, thank the deity), it is certainly reasonable to expect them to be better this year than last, with the possibility of ALL the failings you note being wiped away by shared experience and repetition.
And, yes, Miller has that going for him, as well. Combine the two, and I think questions of being "elite" won't really matter.