I agree with everything and include;
Much bigger world with different area types (snow, desert etc)
More types of enemies.
Moral system that leads to different endings.
Chance to develope friendships/enemies/lovers with NPC.
More armor types and being able to customise them.
Make the game open world to the extent that certain quests will only open up after main story has finished and depending on what moral ground you are on. Even to the point that X many hours into open world and a 2nd main quest starts (can be done via DLC)
