Cool map, it has a great spooky atmosphere. I explored all the room and lit them but I didn't see any mobs the entire time, oh well. After I filled my inventory with loot I went to the beginning and lit the portal went through killed some ghasts AND BLEW UP THE ENTIRE BOTTOM FLOOR WITH TNT! Try spreading now zombie infection! Anyway i dug up to the surface and built a little shed. I think it would be fun to have some kind of building in the nether to explore with some sign based exposition, but awesome map thing i give you 1 2 and 5 :Diamond:!
I think the addition of spawners would give some more mobs to this map.
Just thought up an idea in my head. You could have a mob spawner in a small room that has an iron door on it's only exit. The iron door will be in it's open state by default.
The room that the spawner is in will lead to a bigger room, like the rooms branching off the sleeping quarters for example.
When you step on a pressure plate to enter the area, the sleeping quarters area for example, it will open the door in front of you and also close the door to the spawner. This will allow only a certain number of spawned mobs in the area. The rest would be trapped in the spawning room.
You could even make a secret button somewhere that opens the spawner door and there could be a secret in there.
Also, another suggestion, you should vastly reduce the amount of items.