I agree with #2, sacks are a "sexy" stat, but seem to be a small component of the big defensive picture...
I dont know ... you can make a good argument that sacks are very important. Sacks are not a perfect reflection of defensive pressure on the QB, but they are currently the best indicator that we have, and defensive pressure makes things happen - turnovers, mistakes, rushed throws, etc. They create negative yardage and kill drives. They back teams up deep in their own territory. They take teams out of field goal range, and they turn red zone drives into 3 points instead of 7. They sometimes create points (safeties, forced fumbles for touchdowns). I don't think those are small things.
Let's look at the SB contenders since BB took over as coach of the Pats and their sack totals:
2000: Ravens finished 22nd with 35 sacks, but I'd argue that wasn't reflective of their stifling defense. Giants finished 9th with 44 sacks. In the postseason, the Ravens had 14 sacks and the Giants 13, the two highest totals.
2001: Rams finished 7th with 45 sacks. Pats finished 13th with 41. Pats and Rams tied for most postseason sacks with 7.
2002: Tampa Bay and Oakland finished tied for 6th with 43 sacks. Bucs had 11 sacks in the postseason (a 59 sack pace), the Raiders 6.
2003: Pats finished 6rd with 41 sacks. Carolina finished 7th with 40 sacks. Pats recorded most sacks in the postseason (12), Carolina 2nd with 10.
2004: Pats finished 3rd with 45 sacks. Eagles finished 2nd with 47. Eagles recorded most sacks in the postseason (9), Pats tied for 2nd (6).
2005: Steelers finished 3rd with 47 sacks. Seahawks finished 1st with 50. The Steelers recorded a whopping 15 sacks in 4 postseason games winning the SB as a wild card team, a pace that would have given them 60 over a 16 game season.
2006: Indy finished 30th with 25 sacks, an anomaly. However, they recorded 8 sacks in 3 postseason games, a pace that would have given them 43 for a 16 game season. Chicago finished 8th with 40, and had 7 sacks in the postseason. The Pats had 9 sacks in the postseason, and almost made it to the SB.
2007: Patriots finished 2nd in sacks with 47. The Giants finished first with 53, and also 1st in the postseason with 8 more.
2008: Steelers finished 2nd in sacks with 51. Arizona finished 14th with 31. But in the postseason Arizona recorded 10 sacks (on pace for 52 over a 16 game season) and Pittsburgh 9, the two highest totals.
So it seems like the SB contenders are usually among the lead leaders in sacks, and almost always among the postseason leaders.
The Pats currently rank 24th with 18 sacks on the season, on pace for 29. In the BB era only Indy has made the SB with a worse sack ranking or total, and they upped their defensive pressure considerably in the postseason. That's not a particularly reassuring stat.