Help and Advice
 

1. Having trouble Peck village for the part needed to repair the broken elevator in the first dwarf mines.
2. Where is the elevator that takes you to the train to Medgard?
3. Just moved into the Underground Sea area. Should I clear that next or go searching for the King's daughter among the elves?
Thanks in advance.

1) You will find the needed part of the elevator in the mechanics near the main castle in lower hardar.
2) The elevator to the train is in the eastern part of Taron Mines.
3) It's up to you, you'll get the appropriate quest later.

I think you should at least clear the Dwarves out of the Underground Sea before you make peace with Tom Digor. But if you can defeat the demon army guarding the portal to Demonis you should sneak in there and grab all the loot you can. There will be a lot of new artifacts and spells available.