Who's to say Callahan wouldn't be a bad idea as an Offensive Coordinator? I mean at least I can honestly say he wouldn't run a QB sneak on 2nd and 1

In all seriousness though I would at least consider him at OC. He's from that west coast Walsh tree and I like that as the leading offensive scheme here in Cleveland. That and on defense I want a 4-3 Tampa-style Cover 2.
Why Cover 2? Personnel and scouting wise, we will be better off going to the 4-3. We have the middle covered with Rogers, Williams, and DQ, who is great in coverage and would really benefit roaming in the middle similar to a Brian Urlacher or Ruud plays it in Tampa Bay. It is easier to scout players who play the 4-3, too. Let's work smart and hard on the draft and bolster the talent there. Also, the best way to beat a Cover 2 is to have that gamebreaking TE who is a match-up nightmare and can split the middle of the cover 2. In our division, we have solid TE's who can block and catch but are not the speediest, scary guys who cause one on one havoc like guys like Gates, Gonzales, Winslow, Vernon Davis, etc. That would benefit us, too. Basically our defense could be set with a 4-3 Cover 2. It would be the best way to adapt to our personnel and easiest to scout and add on talent for the future.
That would be the ideal direction of the football team. That's what I would envision at least to work best.