Beaver

Long, winding corridors went out of style a long time ago. They really aren't that fun to fight in because of their lack of movement and tactical options. You can only go backwards or advance, so there's not really any strategy or communication gained from their inclusion.

My advice?
Ditch them completely and go with a substitute for any portion of the map this might cause you to lose.

 

Adding on to this, corridors commonly trap people with no way to escape an enemy, and with the advent of things like armor lock, an entire corridor can be blocked by a single player. Power weapons also become too powerful because there is a limited view. In general, a player should have a slow transition from one area to another, so a player is not caught in the predicament of turning a corner to face someone camping with a shotgun. A completely unrelated problem with the center area in the first picture, besides the cramped quarters like in the other areas, is that the floor created by the rocks is likely to uneven to walk easily, let alone shoot accurately at the same time.

 

if you built this between alaska and montana, I will download it (canada = beaver)
on a side note, if he made his corridors longer, wider, and with more gradual curves, might it work better?

 

It would work best without any corridors (especially since they seem to be a large part of the map), but making a distuingished curve along them, decreasing their size and making them a more natural part of the map, and adding many other routes throughout the map are all things that could help him out.

As for the flooring, just cover it with a Grid or two, and leave the rocks. Assuming it won't cause framerate issues, this could be an aestheticaly pleasing solution to bland gray floors that still allows for decent aiming.