Just a few things I don't see on the list yet.

1. We need non-combat XP. This is not something that would be nice; it is downright critical if you want people to use their imagination and try different things.
2. Stealth in combat needs to be fixed. This is probably a tall order since it involves tweaking enemy AI, but it's ridiculous that enemies don't even try to look for the stealthed archer sniping them.
3. Pressing L Alt should highlight containers and objects lying on tables/ surfaces as well, and not just corpses.
4. Sneak Attack should be melded into the normal attack and only show up when the conditions are met. We don't need another button to click.
5. Adjust starting gear/ equipment not just to class but also subclass, background, and other choices made at character creation.