There are some rules that I do not think make much sense in the NFL. Two of them involve replay challenges. The first is the number of challenges a team gets per game. Each get two. There is a catch, though. If a team gets its first two correct, it is entitled to a third challenge. Why stop there? Why not keep giving coaches additional challenges until they miss? If you get three reviews right as a coach, you have done nothing wrong. You have simply prevented your team from being jobbed. As a result, you cannot continue to do so under the current rules. If he gets three right, give the coach a fourth. If he gets the fourth right, give him a fifth. If he gets the fifth wrong, then he should lose his right.
I understand some might argue that this would slow up the game, but it would make sure calls were right. The real problem would be with the officials blowing too many calls. It would be the only way this would come into effect. A team would only get more challenges if it kept winning them. Once a team loses a challenge, it is no longer entitled to a bonus challenge. That risk would be enough to prevent coaches from reviewing everything.
The second change I would propose would be changing the system in the last two minutes of each half and overtime. Reviews must be initiated from the booth. I still think the booth should be there for critical calls in case a team lacks a challenge and/or a timeout. If a coach still has a challenge, though, I think he should be able to call for a review. Why not?