UGA has Auburn next Saturday. If they beat AU, then they'll have beaten 3 top 10 teams this year, and your scenario would present a lot of problems for the selection committee.
I don't mean to dismiss Oklahoma, Oregon or Utah . . . or PSU for that matter. I just don't think their records stack up with the 5 we're discussing. And that fits with the eye test, as well.
Your comment about OSU not being tested is interesting, because they've played some pretty good teams, including a better-than-expected IU team. If they paste PSU like you're projecting (with reason) and cruise in the BiG championship game, then they'd be right up there with LSU and BAMA.
I think Clemson has been playing to their competition. They're unbeaten and national champs . . . it'd be a travesty of justice to exclude them because their conference has had a down year.