About that image there are a few other things i notice:the this img is spec/phong mask
The lower rock wall textures are overdetailed compared to the floor and upper walls. It doesnt fit tf2. The floor textures is fine to me.
The roofs look very blocky as if its made with regular brushwork. Using displacements might have been a better option to create a smoother looking roof. The way the tiles hang over the edge of the roof doesnt look good aswel. A roof should be looking somewhat solid, bended tiles looks like they cant even hold the rain. Luckily solving this also makes the work on displacement roofs easier. The bumped roofs can still be done with displacements, and in that case it also should be easier.
Maybe go to some existing tf2 maps and check how the roofs are done.
The building support beams are fine.