[Balance]Banshee
I think one of the nasty things about the Banshee level for unprepared/underprepared PCs is the fact that it is quite possible that, upon immediately opening the door to the Banshee room, the PC can die without having a chance to react to her presence. Her room is pretty small--about 4x6, I think, and the range on her wail is a 3 square radius, so the odds of getting hit when you open the door are pretty high.
A few simple fixes might be:
-Reduce the range of the wail from 3 squares to 2, giving a bit more buffer room.
-Greatly increase the size of the Banshee's room. Maybe 6x8 would be appropriate.
-Make the Banshee's wail do damage proportional with distance rather than instant kill in its entire range. Perhaps it takes 33% of max HP per turn at 3 square range, 66% of max HP per turn at 2 square range, and only guaranteed to be lethal if she is adjacent.