There are many items in the overland Ettenmoors that are used for quests. The list of items that are safe to sell follow
- All bear items except Morningthaw Hides and Haunches
- All slug items except Slug meat
- All fellclaw items
- Untreated and Exceptional Hides
- All drake items except for Drake Sinew
- Darktide drops
- Hoarhollow Ale
Drake Sinew cannot be sold, it's a quest item. For the same reason, it will never drop unless you have the relevant quest