Most wanted smaller features for me would be:

1. A button or hotkey to link and unlink all nearby party members (maybe single player only)

2. A toggle to prevent accidentally picking up items that would count as stealing

3. To go with the mis-click suggestion above, a way to target with portraits, or hotkeys

4. The ability to mouse over enemy buffs instead of having to always right-click inspect

5. A highlight/alt toggle, and better highlighting of corpses and entry/area transition points