Reasons why this is a big "no":
1) He is "Mr. FSU". other than Charlie Ward perhaps, there's no other player that identifies more with FSU than Deion. It literally would be like having Michael Irvin ("Mr. Miami") coaching FSU.
2) I watched a celebrity workout session where Deion was the guest. He didn't make much of an effort on his reps, came across as flippant and I was pretty unimpressed. In contrast, Ray Lewis was on that show and he took it so seriously that the host almost passed out doing a portion of Ray's workout. It's a "must watch" if you want to see & understand the work Ray put into becoming the best MLB of all time in the NFL. His work ethic was incredible and his workouts intense & incessant. That is the kind of approach/work ethic that made Miami unbeatable (58-0).
3) Deion never saw a tackling opportunity he didn't want to miss. He's top of the list of players that did NOT want to tackle. He is blessed with unbelievable speed and great vision (which made him incredibly good in coverage & returning kicks) but boy did he shy away from contact. Given our terrible tackling, that's the last person I would want fixing that issue.
4) He doesn't project the right image for the University. Whether you like him or not, Shannon was professional & projected the right image for the school. Deion has always been pretty flashy and it just isn't a good fit from that standpoint.
I do think he is probably a good recruiter. I question whether he would succeed in hiring a serious staff. It's a creative suggestion by OP but highly unlikely (especially if BJ is still the AD -- that's way too far out on a limb for him).