Grimrock

A) Is there a way to access the pit marked 1?
B) After much running, turning and buttoning, I managed to press the button marked 2 but saw no obvious change. What does that button do?
C) In this thread, the area I marked as 3 is described as a secret room accessed via the "Westmost" pit on 6. But it is marked Fighter's Challenge. How do I open the door to that area?
D) If that is Fighter's Challenge, what is this secret room referred to in that thread? Where is the Westmost pit?
E) Is there a way to close the pit at area 4 and grab the torch off the wall? I am sort of assuming it is a trigger to do something like the other torch in that room was.

A) No need. You can access area below through the pit to the south from pit 1.
B) Closes the pit 2 squares to the south so you can press the button on the south wall of the pillar (you need to get a torch from the wall to the north first - this action closes one of the pits to the east).
C) Fighter's Challenge - you need Sword of Nex to open a door (how to get it? look at B))
D) "Westmost" - it's the pit from A) (the room below contains timing door, crab and a treasure)
E) Don't think so. It's just a decoration in this case.