Ok, I don't think the whole converting map formats thing is working out very well. I checked out 2siege, and it had a lot of problems. Pretty much none of the brushes are aligned. There are gaps all over the place. This will cause all sorts of problems, from leaks to poor vising. It doesn't look like you even ran VIS. Take a look at the upper floor in the bases, for example. You walk up the stairs, and the floor doesn't cleanly meet the stairs. There's a small gap. There's also a gap along the middle of the floor. When you run vis, nothing can be hidden upstairs, because things can be seen through the gaps. The floor is also super-thin. I don't think an inch of stone would hold up very well. There are also gaps in the walls and other things, and even on a high-end system, the framerates are mediocre because the whole map is being drawn at once. I'd imagine it's completely unplayable on lowend systems.
Finally, the textures: you need to figure out a way to put them somewhere besides the "bad" directory. Also, you've used some paintball2 textures and included them in the bad directory. This really defeats the purpose of using textures included with the game. a) People will have to download them even though they already have them, and b) high-res texture packs won't be applied to them, because they're in a different location.