It could be in the middle of an open floor, with no visual queue that a ladder exists, and it will still work. It's not depended on surrounding brushes.
I'm unable to look at your map right now (as I'm at work), but in dm_lockdown, VALVe wrapped their ladders in a bsp block textured with player_clip, so they never actually touched the ladder.
It's a matter of opinion, really. I agree that there is a ton of potential overall.
I did have a ton of fun playing team DM on overwatch. It became a battle for the top floor, and control went back and forth. Whoever held the top got the rocket launcher and could control the only path up, but...
Everyone should read the Prima "Raising the Bar" book if they're interested in all this. There are some writer's notes about the origin of Gordon Freeman (no metaphor: just referencing favorite scientists names). City 17 is a conglomeration of architecture from a number of eastern European...
I think the prison was supposed to have been cleared out, as that was where they were working on the teleportation technology (thus the presence of the teleporter at the end).
Playing around with similar URLs, I came across this:
http://www.steampowered.com/test/pwned/
Doubt that it's anything, but I guess I could throw it out there.
/edit: it's nothing. try this:
http://www.steampowered.com/test/nova/prospekt/
oh well.