Nice theme you have here, good use of fog to blend the map into the skybox. One major thing I noticed straight away was the absolute silence in the map, no wind, no ambiance, no water etc. It was just me and my footsteps.
A simple soundscape would do wonders on a map like this and doesn't even need to be complicated. As I said, a little bit of wind would be nice to hear.
I think you should probably add Valve to the authors list since you are using their buildings from the coastline levels in HL2. Might not want to rely too much on using valve content as its fairly recognizable and make people think about that game rather than CS:S and what their currently doing.
Some visual things I noticed while running around the map were:
Small glitch in one house by the fireplace, some brush overlap, easy fix.
I noticed on the one building with the destroyed wall section that the lighting wasn't right along the outside wall as there was some extra shadows from nothing. Took at look and its because you've left in all the sides of the displacements used to create the destroyed wall. You need to destroy them otherwise you get odd shadows like that. Nodraw doesn't do anything for displacements.
This is a bit of a big issue:

Those are the only areaportals in the entire map - two sheds.
Areaportals and areaportal_windows make huge performance boosts in maps like this, I'm pretty sure that the houses contained them in their original format but you've removed them when you made this one....
Using areaportals/windows for all exterior holes in the houses would make this map perform absolutely amazing as there is little detail when outdoors, its all just exterior faces of the buildings and fog. Not much else needs to be rendered; However, as it stands now most of the models etc within the homes are rendered at all times for the most part.
If you are going to make another version of this map I would seriously consider re-adding in the optimization it needs. You'll see just how much of a difference it can make.