Here's my list:
- Bring back the yield while keeping the u-turn.

- Speedbump / Hazard now becomes something similar to yields and u-turns. (though I doubt this very much)
- Try placing more NELs in the first few legs if possible. (I know, budget

)
- The pole mentioned on the 1st post.

- More different types of music.

Also, bring back some old ones.

- Let fans around the world vote for the returning teams for the next returnee season.

(my favorite)
- Add new twists every season.

- Bring back teams from older seasons or bring back teams that were eliminated on or before the 4th leg.
- Cast 12 teams once in a while.

- New NEL penalty.
- Bring back starting line task. (with or without penalties; better if no one gets eliminated on the starting line)
- More Fast Forwards?

About 3 to 6, no FFs on the 1st leg and the last 3 legs.
- 2-hour premiere.

Either it is 1 long leg or it is 2 legs with a NEL/TBC on the 1st leg.
- Keep 2-hour finale every season.

- Put 3 yields and 3 u-turns each race. (I wanna see one on the 1st/2nd leg.)

- Visit more exotic locations. (I loved the Bora Bora visit from last season.)

- More flight drama!!!

- Good edits for all teams.
- Casting teams with unique professions.

And more! That's all I remember for now, but I might be forgetting something.
As I went on, I realized that this is similar to a wishlist thread.