I did address that first point in my writeup, but it makes less difference than you seem to think. The 22 worst teams in my study (average record: 8.2-7.8) gave up an average of 375 points (while scoring 394), but on average their defenses were quite a bit better than this year’s Indy D, esp. when defending against the pass, in which case they most certainly are not capable of playing to that one strength, as you said. 8.1 yards per pass play (2010 by comparison was 6.1) is a tough thing for any offense to overcome, and I don’t think time of possession (which in the case of the Colts decreased by 5 minutes from '10 to '11) or anything even vintage Manning (remember, last year was in many ways his worst) could do is going to affect those numbers too much. And if the games were more competitive, that would mean that teams would be making even more hay (yards and points) out of Indy’s porous secondary, even if Manning is on the field for his extra 5 minutes. It also works both ways too (i.e. crap defenses are on the field longer), so I doubt that entire 5 minutes can be laid entirely at his feet.
If you can find any playoff teams which have allowed even 7+ yards per pass (net), knock yourself out; here’s 2011’s main team stats page-you want “ANY/A” in the passing defense table.
[The 8.8 figure in my other post was AY/A, not ANY/A: only difference is that the latter factors in sacks.]
The hell with it: since I am bored, here are the worst pass defenses to make the playoffs since the 1978 rules changes:
2004 Packers 10-6, 424/384 points, 7.0 ANY/A on offense, 7.1 defense.
Started 1-4, won 9 of their last 12.
2008 Cards, 9-7, 427/426 points, 7.0/6.7 ANY/A.
A lucky team in a weak division.
2005 Pats, 10-6, 379-338, 6.8/6.7 ANY/A.
A weak team compared to the '04 and '06 squads.
1997 Vikes, 9-7, 354/359, 5.4/6.4 ANY/A.
Another lucky team, this time a wild card.
1986 Jets, 10-6, 364/386, 5.6/6.6 ANY/A.
The Immortal Ken O’Brien at the helm.
Okay-so yeah, if you have a HoF-quality QB at the helm (Favre, Warner and Brady in the above seasons), he might be able to overcome a crappy pass defense. [Note that the times such teams failed to make the playoffs at all had to greatly outnumber the 3 instances above.] Or get lucky in a weak division and/or league with no good wild card teams. But note that the Colts aren’t just bad, like the '97 Pack was, but historically awful, the worst that I was able to find, and probably the worst in the entire history of the NFL (I doubt any team before 1978 was allowing 8.1 yards an attempt). That’s a lot to overcome for even a HoF-caliber QB at the top of his game, much less one on the decline.