Some things I don't agree with:
Chris Harris B+, I think A- would be more appropriate, he was the best CB on the roster in the majority of games, made plays on the ball and held tight coverage very consistently - his only really weak game was against the Texans.
Mike Adams B, I think a C or C- would be appropriate, he was a non-factor in coverage all season and his run support was spotty at best.
Keith Brooking B+, a generous B- would be better, he only really did good work consistently in short yardage situations, in most game situations he was a liability.
Wolfe C+, a flat B would be do it here, he exceeded reasonable expectations by some margin and played more snaps than I think anyone could have predicted.
Vickerson, Bannan B-, these guys were the main reason the defense was as strong as it was, they consistently held the run game in check by sealing gaps and playing very disciplined, a B would be appropriate.
Matt Willis C, I would give him an F if I felt spiteful and at best a D-, every time he was on the field on offence it was about 50/50 if he made a noticeable mistake like running the wrong route.