Major suggestion for me is one that is in just about every game that pisses me off royaly.
"No Show-stopper Puzzles". A perfect examples is that stupid rune switches in FoV. It was so vague, so pointless and so hidden that I didn't even know about it untill asking on the forum "what the hell do I do next" after talking to every damn npc I could find.
If that content was for a bonus or "easter egg" deal then it would have been fine, though it basically stopped the game for 2 hours which severely ruined my enjoyment.
Character should die when they fall really far, gotta have some sense of reality.
Other than wanting to see flowing long robes, capes, flails and staves in the next game that is pretty much my only complaint.
Not bad, only 3 things that bugged me and the last two were nothing major.
Don't reuse turning into a dragon (though riding one would be just as fun) as it has already been used.