Leading off with the obvious: no system will be perfect and there's always going to be some controversy. March Madness is the largest playoff system in the NCAA DI sporting landscape...and even that has its controversies when you're trying to figure out who gets "in" at the bottom seeds and whether smaller programs get the nod over Power 5 midtable conference teams.
The regular season matters...rivalry games matter...and bowl games *should* matter. So how to revamp the system that protects all the above?
I hear the argument that the old-school formula of #1 vs #2 was the "best" at preserving the regular season and generally ensuring quality bowl games...but we aren't going backwards for two reasons: money and the media.
The money part is obvious; and the media exists to stir up controversy. In the BCS era, there was perpetual whining about the #3 team that was left out (Auburn's a good example); but also teams like Boise that were undefeated and "deserving of a chance." In the playoff era, that's switched to UCF, Cincinnati, and to an extent, BYU. I feel for those programs--and while I've no doubt they aren't even close to being able to compete for a national championship, who doesn't like the idea of an upset by one of those guys over a team like Ohio State or Clemson? I'd enjoy the hell out of it. They'd lose the next game--for sure, but it'd be a fun ride along the way.
Here's a workable solution for an 8 team playoff: take the top 8 ranked committee teams and have them duke it out. The cream generally rises to the crop and let's face it: the top 1-4 teams are usually undefeated every year anyway, so regular season will still matter. This rewards stronger conferences like the SEC too--since the committee factors in "the eye test" and strength of schedule. Sorry, I've seen enough of the Pac 12 getting hosed by an SEC team in a season opener, then go on to coast through that joke of a conference and be generating playoff "buzz" later on. There's plenty of in-season marquee games between the various conferences that establish the pecking order and that should matter. Ie: if Oregon loses to Auburn in week 1...Auburn loses to #3 LSU and then #1 Bama...why should a one-loss Oregon team be ranked above them when Auburn would have played 4-5 top 15 teams and Oregon only one (that they lost). Things like that have me against making it mandatory for all Power 5 conference champions to get a playoff bid.
Expanded playoff means more revenue--use that to increase the pot for the smaller bowls. Nothing ensures that coaches and players turn up more than more revenue at stake.
Opt-outs are tricky...but the main reason players do it is because there's a--valid--fear of injury. D'Eriq King got hurt yesterday; and so did Ehlinger. King's injury looked more serious. Two solutions immediately come to mind: immediately grant an extra year of eligibility to all seniors who get injured; and also: use part of the expanded playoff revenue to set up an insurance fund for players who get injured in a bowl game. Taking some of the risk out of the equation will cut down on this more than we have now.
The NCAA needs to throw some weight around and have the NFL get on-board with things too...ultimately, players opting out works for them and the NFL--but not for college football as a whole. Have the NCAA change its rules and say that players need to complete the season AND bowl game if they want to be draft-eligible. The NFL probably wouldn't like it...but they're completely dependent on the college game to send over players every year, so use that as leverage to ensure bowl games stay relevant.