I agree with everything he said, but would like to add:
MLB, DT, and RB are the 3 biggest areas of need imo.
Mike, Brookings played amazing and saved our season imo, but we need a true leader/thumper in there that is young. Look what Rey did in the play offs. I love Brookings, but he cant do that.
DT, imo our biggest need. I like who we have as rotation players but we need a true pass rusher/run stopper. You look at ever elite defense that wins Super Bowls.. Tampa, Ravens, Pits, etc.. they all had elite top level DT. I understand finding someone like Watt is hard as heck, but we let a pretty good DT go to Saints last year for pretty cheap (rather have kept him instead of 15mill on Mayo).
RB, I really like Mcgahee and Moreno (saved our season with his running when he came in), and I like Hillman (played well for a rookie in playoffs), but you look at most all elite offenses and they have a RB that can get the hard 1-2 yards but can also bust 40+ TDs. Did we even have a rushing TD over 30 yards this year? If we can find a great back I think our offense is complete. Our WRs and TEs are great, but with no run game it can be shut down (look at Ravens game).
We need to add depth at OL, DB, and FS/SS as well. I like Moore, he made a horrible play in Ravens game, but so did Champ and every other player. Adams needs to be replaced, and you can never have enough DBs. Hopefully Carter can replace Adams.