I've attached a demo with suggestions for fixes. My biggest complaints are the flag placement, barrel texture alignment, and r_speeds. More details in the demo.
Put it up on the beta server and played it a bit. It's almost impossible to get flag captures, but it's still kind of fun. I would bring down the railing height on the side stairs as they're just high enough that you can't shoot over, but low enough that people can see you're up there, so it's a bit of a death trap. I'll PM you the server details for how to play your map on the beta server.