I will agree with the poster who said that you wayyyyyy over analyze the whole spread offense/LB/can't hold up, "toughness" of the Big 10, etc.
When we lost to texa$$ last year, I believe that both Compton and Fisher were out injured, so essentially, we had David (normally who would play Weakside) playing Middle, and we had 2 safeties (Hagg and Gomes) filling in at spots. Essentially we were running a 4-1-6 defense. You won't see as much of that this year.
Against more traditional teams like Wisconsin and Iowa, I would be willing to bet that we see more traditional 4-3, as well as some fronts with 3 DTs, where we can run anything from a 3-3, a 4-3, or a 5-2 front depending on the situation.
As for #2 and the rest of the bolded, well, the way that the Big 10 defenses showed up in the bowl games say differently.
I'm more worried about our offensive execution than I am the defenses we will be playing against this year.