Nice topic.

"My airline" would offer fares dependent upon how much business you were giving/willing to give to the airline. You would get very good prices with few or no restrictions in return for real loyalty measured by gross profit contribution and adherence to forecast travel plans.

Fares would be far lower than Y or B fares, but a bit more than leisure fares.

I would have a one class cabin with comfortable 2 X 2 seats, perhaps in a fleet consisting only of either A320 or B737s.

I might do a hybrid point-to-point model with small mini-hubs, using primary airports to make interlining and connections easy.