As a lifelong NASCAR fan I think it could be so much better and here's just a small list of things I would personally do if I ran the sport:
1. The schedule - add a couple of more tracks to the schedule. First, I would eliminate one race from each of the following tracks: Pocono, New Hampshire, California, and Atlanta. If I could I would take one from Michigan too but I know that track is strategically located and that would never happen anyway. To replace the 4 races above I would add Nashville, Kentucky, Iowa, and Montreal to the schedule. NASCAR doesn't need to start racing all over creation but I think another road course would be a good fit and Montreal can accommodate the NASCAR Cup crowd much better than Mexico City can. Also, rearrange the Chase so there aren't as many cookie cutters in the actual Chase. I say put Bristol in the Chase as well as a road course at least to give a better mix of tracks.
2. Ease off the drivers and let them fuss and fight a little. My lord, NASCAR was BORN in 1979 in Daytona Beach - at least to the masses it was. Ken Squier with one of the most famous quotes in racing: "and there's a fight."
3. NO COT for the Nationwide - come up with a cheaper car instead of making owners come up with more money that some cannot afford to do. I liked the idea of having smaller V-6 cars for the series and making them totally different than the Cup cars and helping the series gain its own identity.
4. On the LAST LAP of any race you race back to the flag - period. I know some people whine and cry about safety but I think a race needs to end at the line on the last lap. It cheats fans out of money when a race ends by the scoring loop or where the cars were on track when the little yellow light came on. When they are racing to the flag everyone knows exactly where the end of the race takes place. This is my biggest pet peeve in the sport. The Lucky Dog can stay since they won't let them race back to the line under normal cautions. But on the last lap I say you race back to the line.
5. At about 15-18 races the teams arrive to the track a day earlier than they do now. This would be the new testing policy. Teams would have the option to arrive to the track one day early and test. This would save teams a ton of money since they are always testing anyway the way it is.
That's the main things I can think of right now. There are other things that I know I'll think of but those are my biggest problems with the way things are right now...