Also maybe remove blood money? It makes gold too easy to come by I think.

I think that the spirits don't really do enough scouting. I think this would be made better if the hidden rooms with the neutral enemies were behind locked doors. That way the spirits would be able to scount ahead and find them. As it was I scouted the southern portion and decided not to go there because I didn't realize there were hidden diggable rooms.
You could also put in a spirit chamber which would give you another use of your spirits, in levelling up your minions.
The fact that there's an arena you can build and I don't think I noticed a beastmaster anywhere isn't super useful. Maybe put one neutral beastmaster with the beast lair?

You can use the torture chamber to execute prisoners and turn them into spirits for scouting out the caverns.

I do rremember this being a very difficult map, and it remains that way. The only comment I have is that I do not understand why you included a torture chamber, but no access to a Succubus, unless I missed finding one.