Several bottles at the Toll House basement cannot be looted because they are supposedly out of range. At the most, you could only get the front three bottles on the top right shelf.
If you interrogate Kagha's corpse, there is also a line of text about the death of the Tiefling girl. But Arabella is still alive (in my playthrough)....
After breaking the Ritual of Thorns, Maggran can be found to the west near the Bard Alfira. In both of his dialogue scenes, you can hear the sound of speech and see his upper body in motion, BUT his lips don't move at all during his statements.
The spell Speak with Dead is displayed almost outside the hotbar...
In the Fetid Bog there are several wooden boxes and wooden crates, which were placed identically inside each other. If you loot one and then add it to your inventory, a copy remains, only the random content of this particular case is different. The screenshot shows how I pick up the supposed original, but a duplicate remains.