I thought the reason the playoff system was started was to ensure teams got a just to decide the National Champion on the field. BCS got us out of the conference alignments with certain bowls so the top two could play each other then there was the discussion of three undefeated Power5 schools at the end of the season and BCS cannot solve that on the field.
My whole point, the CFP was made to decide the champion on the field. I think the message has warped to be the "4 best" at the end of the year (as subjective as that is) instead of ensuring conference champions play each other. I don't think there should ever be two teams from the same conference in the CFP. You had your chance, if you didn't win your conference you don't get in.
The wild card will be Notre Dame until they join a conference but it should always be at least 3 Conference Champions and usually 4 Conference Champions.
The committee would stick to the original idea much better if the rankings were simply put out as above the line or below the line.
This would also prevent the committee from getting caught up in, "well they were #1 before they lost and lost to #7 so it shouldn't knock them out of the top 4.
4 teams above the cut line and finish the group with everybody else below the cut line.
Instead of worrying about 21 teams below the line, they could just include teams that have a chance to move above the line. The season starts with everyone in the country on the list and shrinks throughout the year.
The idea of ranking 25 teams like the last 15 or 16 have anything to do with the committee's job creates problems and distracts the committee.