Sorry for the late feedback. Here it is, since you want to do the final release soon.
The sun angle doesn't fit the sky, try something like "sun_angle" "90 -40". That would also help a little bit to get less shadows because of the high walls.
The chrome barrels are useless if all players start with steel barrels. I'd replace the with some more ammo items, maybe.
You added "trracer" "trracer" to one the purple player spawns. Delete that to fix the bad field warning while loading the map.
And some screenshots...
Red: I'd lower the edge to the ground high of the corner.
Green: It would be cool if you can try to improve the alignments of these brushes like you did on the purple side.
Red: I'd would align them that the black line of the texture is in the mid of the brush. Move the faces that the black line fits the black line of the other faces.
Red: This one still needs to be rotated.
Red: Misaligned.
Looks a little bit empty. Maybe you could add the flag texture at the red (mid) or the green (left and right) marks.
All in all a great job so far
I'll upload the beta 5 to our beta server soon, that you can test the map and the gameplay online, if not done yet.