I think 8 conference games is about perfect. Part of the fun from a fan's perspective is playing new/random teams every year, and if there are only 2-3 non-conference games that's going to be seriously reduced. I really doubt teams will stop scheduling at least 1 FCS cupcake a year (if not FCS, then a team from the very dregs of the FBS), and most schools will also play a second relatively easy game against a team from the Sun Belt/MAC/Conference USA. For everyone but the Alabamas and LSUs of the world, that makes since. If you're searching for 6 or 8 wins it simply doesn't make sense to have 10 or 11 tough teams on the schedule. If you think you're going to qualify for the 4 team playoff and you're worried about SOS, then schedule 4 tough teams out of conference. Play Notre Dame or Louisville or Texas instead of whatever Sun Belt team you have on the schedule now. And let everyone else who just wants to get to bowl game schedule how they need to.
Also, if you expand the schedule to 9 games, you're at most going to get 1 non-conference game against a major opponent, if even that. So the Georgias, Floridas and South Carolinas of the world will be playing their rival and two cupcakes most every year. Same for Mizzou whenever Kansas decides to play us again. Which means there's no chance to play a random/fun game against a team from the Pac-12, ACC or the Big 12 if teams want to, and I'm not sure that's what anyone wants.