I have gave a lot of thought into this and I would like to present you my final thoughts.
For example if you play certain amount of hours and you have been constantly avoiding the main storyline(exploring or side questing) similar to Oblivion where if you didnt want to play it you simply werent triggering the main questline.
What do you think of sudden dragon attacks on villages or main quests forced upon the player in Skyrim?
I have come upon this conclusion since the radiant story creates the quests for example if you throw a sword down on the ground or kill someone in some part of the game so the game creates a side quest in some part you havent explored yet, and by visiting that part you trigger some part of/or main quest, because of the same location you supposed to go.
Second of all by killing someone or something.I have to return to Oblivion for you to understand my thoughts about this one, for example I know a lot of you know about the Umbra sword just outside the Imperial city on the North/west side.You could simply go to that dungeon and kill the witch and obtain the Umbra sword not knowing that you completed one of the side quests even before you obtained it.I think that this issue should be adressed to, so that we dont do something before the game actually plans for us to do it.
My fears for the radiant story are valid, because I dont want the game to mess itself up in some stage.
I hope that the main storyline will be as much ''cut off'' from everything else as possible, even if that means you not being able to go somewhere before reaching certain level or quests.