Unless you want to farm specific MIs or Reaper, you always go friendly with them. They're easy to gain faction rep with (killing chthonians) and they have decent augments until you play through FG content or reach malmouth. Honestly it does not matter much unless u want to improve your kill speed by few seconds.

How do I get to Barrowholm?

Barrowholm can be found in the north of Ugdenbog, and Scorv Egdenor inside his house in the village. On speaking with him you will have the option of being friendly or hostile. The A Jewel in the Mud quest will then activate, which will play out differently depending on your choice.

How do I open Barrowholm cellar?

The Forlorn Cellar is an underground area in Act 5. It has one entrance/exit located just outside Barrowholm in Ugdenbog. The Cellar can only be accessed after killing Scorv Egdenor during the A Witch's Bargain quest.