All rivalry games can be protected by having you pair with one pod to form a division and allowing the 8th conference game be played against a protected rival. Correct pod formations like I've noted above will keep all protected rivalry games intact. It also opens up new match-ups to be created.
Penn State - Ohio State would be protected
Nebraska - Missouri would be protected
Michigan - Michigan State would be protected
This holds onto 6 teams out of 16, meaning you can form 5 more protected match-ups and create even more rivalries for the future. There will undoubtedly be very little expansion after this for a long time.
Keep in mind that travel costs figure prominently into division/pod assignments. Nebraska and Pitt are not going to want to play every year due to the cost of travel.
I have a feeling travel costs will come out of the Television revenue with a cap on spending to ensure that people are not abusing it. There is no adequate way to add the Big East teams, protect the tradition and ensure that all geographical pairings are optimal. Maybe something like $XXXXXX to any away team travelling over YYYYY number of miles.
Agree that no set is optimal. But I think travel costs will trump a few of the "lesser" rivalries; even if the conference pays for it, that's money out of everyone's pocket. The B10 will have to make a few sacrifices to make this happen.
While we're talking travel costs, here's our mileage breakdown to each venue from closest to furthest using the shortest route suggested by Google Maps. This assumes Mizzou, Syracuse, Pitt and Rutgers in the big 10.
Iowa City, IA. = 301 mi. (4hrs 57mins)
Columbia, MO. = 324 mi. (5hrs 21 mins)
Minneapolis, MN. = 433 mi. (6hrs 54 mins)
Madison, WI. = 495 mi. (8hrs 2mins)
Champaign, IL. = 524 mi. (8hrs 36mins)
Evanston, IL. = 527 mi. (8hrs 40mins)
West Lafayette, IN. = 624 mi. (10hrs 4mins)
Bloomington, IN. = 637 mi. (11hrs. 5 mins)
Lansing, MI. = 722 mi. (11hrs 22mins)
Ann Arbor, MI. = 746 mi. (11hrs 59mins)
Columbus, OH. = 823 mi. (13hrs 23mins)
Pittsburgh, PA. = 966 mi. (15hrs 50mins)
University Park, PA. = 1,072 mi. (17hrs 31mins)
Syracuse, NY. = 1,182 mi. (18hrs 55mins)
Piscataway, NJ = 1,303 mi. (21hrs 11mins)
Total = 10,679 mi.