I like to start out by saying I'm not a lawyer, accountant, or any other type of ‘professional'. I have an Associate's degree through the military and I work on computers. With that out of the way, here is my solution.
First of all knock the preseason down to 3 games. 95% of starters are known before game 1, and while they play a little during the preseason it is not enough to warrant 4 games. This will still give rookies and recent free agent signees enough time to prove themselves. But in my opinion if you haven't impressed the coaches in practice and training camp, then I don't think you can make that much of a difference.
Now make the regular season 18 weeks long (right now it is 17) but keep teams playing 16 games. This will do a couple of things; 1, teams will have 2-bye weeks. No longer do teams have to worry about having their bye week in the beginning of the season or the end of the season, with 2 weeks they can be spread out, and give players more time to recover.
2. There will be an extra week of games on TV; more weeks mean more television revenue. Now while your teams will still only be on for 16 games, let's be honest football is football, and we all have a second favorite team we watch. My favorite teams are the 49ers and whoever is playing the Giants.
Plus since players are still only playing in 16 games, there will be no need to rework contracts.
I feel that the idea of a rookie salary cap has been beaten to death, so I won't address it, I will just say I think it is a good idea.
But the point I am trying to make here is extend the season, and give teams 2 bye weeks. I believe it is win/win. What about you?