Where Only Fools Dare Tread

Monster(s): Venomous Skiter (guns); Ghast (guns); Greater Nightmare (armor-piercing gun ammo, projectile grenades)

Saving Zone(s): 3
N of S center.
Near SE corner.
N of center.

Teleporters:
Between the two Southern Saving zones: back to But Wait! - That's Not All! 
NW area: on to the 4 teleporter rooms leading to Who Else Wants Some?

The map above shows the layout of the teleporter rooms.  The straightforward way through is to enter room 1, turn right and teleport to room 2, go straight across and teleport to room 4, walk forwards turn around and go back through the teleporter behind you. 

Objectives:
Clear Blue Potion SW of center/NW of the between S/center Saving Zone
Dead Cuban Soldiers: SW corner
Gold key: with one of the Dead Cuban Soldier
Black Crystal: around N center

Problem(s): Several Four/Three-T rooms
Solution(s): Follow map above.  Remember to be fully rested before going through the last teleporter in room 4.