If they did go to a 18 game season my hope would be that they'd pick up another inter conference division and play them or pick two teams out of each remaining inter conference division. That way you'd get the best of the best out of each division come playoff time. Just my two cents, I'll take my change now.
As for when they'd schedule them my suggestion would be to take the two of the preseason games away so that you have a game to get the starters up to speed in the first half then play everyone else the second half. The second game play them for three quarters and then everyone else that last quarter. That leaves two weeks that would have been pre season games. You take one of those and make it a regular season game and the other and make it a bye week at some point in the season. That leaves one game left to take care of that you remove the week between the last playoff game and the super bowl. The pro bowl is meaningless and has been so play it the week after the super bowl. Again, just my thoughts.