Thanks for all the feedback!
To be honest I have no idea why all the lights ended up yellow.
I did some fiddling with the settings though, and found out that they all had env_lightglow entities on them that were set to "255 255 182," giving them that Jarate-esque tint. I guess it's the result of my using light setups from the Light Effects Gallery .vmf in the downloads section, which for whatever reason has the lights that color. Might have to edit that file to get white lights from the get-go. Anyway, they're all set to solid white now.
None of the current textures are permanent of course, but I've changed the interior floors to "Reflectivity 70%" anyway to aid in navigation until they get detailed (they'll probably be concrete in the end).
Yeah, the sightlines are something I was worried about. I'm adding some more cover on the bridge in about the same places you drew it in. Here's a Hammer preview:
You can also see that I've added more routes leading out of the pit.
In addition to sheltering the bridge, the new cover seems to eliminate snipers' ability to see all 3 top-level exits at once, but from the sides they can sometimes sort-of cover both the side ones if they're at a certain angle (not as well as before, but can still see to both). Still working on that...
Currently I'm working on those side entrances at pit-level, then I'll be able to compile and re-test it all. Here's a preview, though it's just the floor right now:
Other smaller changes are being made for a2, including the whole pit floor being shifted down slightly - it didn't line up on the larger Hammer grid sizes as everything else does, and it was bugging me. I'd say you can probably expect the next version to be up sometime today.