I will agree the game is probably balanced towards 3-4 players (im running for 5, and despite my efforts to buff the combat encounters they are mincemeating most things).
But do wanna ask:
How often do they have to roll for things?
The game advocates to only roll when the players are trying something risky/challenging. Sense they are using an item (the rope) i let them climb down without rolling for anything.
Did they provoke the ghost into attacking or did they just start swinging at her as soon as she appeared?
I usually like to make the ghost sympathetic, and allow the players to earn her trust (such as bluffing that they are part of the empire, fetch the silver bands from the childrens coffins etc), and they can gain her treasures without resulting to voilence.
Plus there are two magical torches the players can use in a pinch.
The Wright is indeed a nasty foe, but i use him as a "lesson" that sometimes (especially how vunerable you can be) fleeing is better than to stay and fight to the death. I will have him move around to scare them, but i only bring him out when they have looted the crypt. If the players realize they can't do much against it, i'll point out they have the treasure and could just leave. It can lead to a tense scene of the players trying to escape.
Good questions and points!
I think the bulk of this can be put down to me running the adventure mostly as written.
The acrobatics check to descend is written into the adventure hence why I called for it (with a boon using the rope).
I ran the ghost as friendly, but unintelligible without the languages check (as per the adventure!), and even then you can only make out key phrases about the dragon empire and Eledain. She then became hostile, when they took the warhammer. In the adventure it says she respawns and then becomes hostile if they enter the oak door, I didn't have her respawn after a stretch - but after a whole shift. And then she remained peaceful when they entered the door!
The Wight sounds better as you ran it - again I had him there as written (they'd previously drawn his attention and defeated him on a previous day!) standing over the sarcophagus. This led to the inevitable!