Definitely fog of war is needed. Seeing all breaks the mystery for me (that was the case in DOS 2). Would love to see the unseen world blurred/greyed or just plain dark.
Remove fast traveling from any point. Tie it with travel points on map spread around the world in "safe" spots. Also, connect these "safe" spots with long rests, so that only in certain places you can "freshen" up. I want to travel, I want to move, I want to take my time and walk to certain places, without instant transmision. Oh, and maybe add a chance for a random encounter if we happen to revisit already seen places?