While all the ideas are excellent fodder for discussion, remember MLB is a business. Those who control it are the owners and the player's union. They will only make changes that suit their financial interests. In the player's case it is to have as many players make as much money as possible. In the owners case it is putting fannies in the seats and eyeballs on TV screens. It is unlikely that either party would agree to any major realignment unless it meets their interests. The obvious advantage to the current system is there are six division races and a balanced alignment. It is likely, however and even probable that realignment to a two division format in each league will happen once MLB expands to 32 teams. Until then it is doubtful.
When and if MLB expands to 32 teams there will be the major issue of total realignment along geographic lines. One would expect that there would be a great deal of pressure to have all of the California teams, Angels, Dodgers Padres As and Giants in the same division in the same league with the Mariners Dbacks and Rockies depending if Las Vegas gets an expansion team.
I'd love to see how fans in NewYork would react to the Mets and Yankees in the same division. That would be a hoot.