Somthing I found interesting is the following.
Orcs and Goblins are less resistant to Light Damage ~ I have not seen a scroll drop for that so far in the Mines.
Something that would have been handy considering the number of them swarming around Moria.
The scroll drops/rewards are applied to your legendary weapon so you can adjust the damage type.
Half Orcs though are less resistant to Beleriand.
I picked this info up from the Lotro WiKi so dont know how up to date it is.