Regarding pressure on Brady, that's the #1 thing although it's not my #1 key because I'm not worried about it. I don't have the tape of the first Denver game but that was just Kaczur's 3rd game at LT and we had Pass as the starting RB. Kaczur has now started 11 games since then so he's much more comfortable at LT and working with Mankins so blitzing and general pass rush should bother him (them) less. Add to that an actual run threat with Dillon/Faulk (I know Pass did well in that Denver game but he was no threat going into the game, as soon as they saw him in I doubt they were thinking run much) and I'm not worried about pressure. Looking at the Jacksonville stats, I'm shocked to see they had 4 sacks because I don't remember them. But Jacksonville is among the league leaders in sacks and we generally protected Brady very well. Denver is near the bottom in sacks and I expect the now veteran left side to do fine and I hope Denver brings extra guys. That said, the OL will have some problems with communication due to noise but overall they should be fine.
No doubt for me, the #1 key is stopping the run. Sure, Plummer has had a good season and making them pass plays into our biggest weakness, defending the pass. But I'm confident we'll make enough plays if we get them into 3rd and 5+ consistently, especially as we won't need our #3 and #4 CB in too much and that's our biggest weakness.