Another change needs to be made regarding player injuries on the field. We have seen for years (Joe Gallat used to be the absolute worst) that when the defense has been on the field a lot during a game, and they are very tired, someone will fake an injury so the rest of the team can get a breather. Of course, after three plays, if that defense is still on the field, miraculously, that injured player who couldn't move for 3 - 4 minutes, trots back onto the field.
What should be done is: unless the player is unconscious or in need of a spinal board and neck brace, in which case he would be disqualified from any further play during that game, a golf cart should be immediatelty dispatched onto the field to remove the player, in which case, he still misses out on the next three plays.
This would speed up the game and make it more interesting for the fans.
The other problem is, as someone else mentioned, the Refs. Someone has to make them more accountable and remind them that the game is not about them. Many years ago, I had Bud Steen over to my house for dinner. Bud is/was a nice guy, but when we talked about the whole reffing thing, I got the impression that the Refs considered themselves to be a bigger part of the game than just enforcers of the rules. Long story short, find a grading system for the Refs. Too many good plays being called back by penalties that are unrelated or called wrong.