Well,it says main quest in the list.And Wrothger when you have quests there.Same with the other areas.They can just be clicked on or not to show the quests.If you want to concentrate on your main questline open it up and click one active for it to track in the upper right of the screen.The others are just dormant.
What I would like the Quest Tracker to do is to go to the next stage in the quest when I finish part of a multi stage quest. I think instead it goes to the oldest, or maybe it's the lowest level quest in my log so I start running off in the wrong direction. And, I get lost easy enough thank you very much.