If I were you I would delete that map and start over again. The map is really shabby. And are players supposed to be able to go under the map? If not, you should try to make a better sky:
That will improve performance and shorten compile time.
And why did you make the ground 1 unit thick!? I see no reason for doing that, it just makes aligning brushes a nightmare having to zoom in/out all the time.
As I said before, compile the map with VIS and RAD on. Without VIS the game will render the whole map at once, which in your case, probably causes the game to choke.