No, you do not have to delete any of your saves. The mod and the game are two "different" games, you will have independent saves and campaigns for each of them. So when you start up RTR, you will have to start a new campaign and create a whole new save.
I have dedicated my life to Auron66, my lord and savior. I love you Auron! <3 (I love you too Boxxy :3)