You want styling critiques? Okay, that I can do for ya right now.
Shot #1
-Your roofs are way too thick, they look to be 32 units or so thick, they should be 4 units maximum if they are using that metal roof texture.
-Your walls are insanely thick in this shot and it makes your door ways and especially your window frames look weird as hell being as deep as they are.
-Your rock displacements are random and jagged, nothing looks good about them currently. Try building a nice shape out of brushwork before converting it to displacements to give yourself a better base for how it will look and you will have an easier time adjusting them to look good.
-Your window frames in the background behind the rock displacements are touching the roof, this is a no-no in both the visual department and the realistic geometry department.
-Is that a path to the bottom left in this shot? It seems awkwardly built. Also thin out some of the wooden brushwork in this map, no one likes super thick beams everywhere.
Shot #2
-Same stuff as shot #1 comments
-Spawn door is dark, but I bet you knew that.
-The displacement lump here looks like it might be annoying for smooth walking about
Shot #3
-I am critiquing your styling here but there almost isnt any. You have a massively thick floor with glass coming out of it and no trim or anything? That looks really odd.
-Ceilings are way too low, take a look at official tf2 maps, the scale is much larger than other source engine games.
-Your ceiling is flat and using that metal texture again, it looks weird.
-Why do you have those small light fixtures near the floor in the background? They are just plastered on the wall with this random light blob around them. Try messing with your lighting settings to get clearer lighting. ALso, sprites and light glows make light prop appear on, use them.
Shot #4
-Nothing really to say here besides my lighting comments in shot #3
Shot #5
-That concrete texture is a wall texture. Unless you use it well, it should remain a wall texture, it looks weird being on the floor here.
-Your windows are touching the roof outside and the ceiling inside and it looks massively weird. Stick to using window frame props for your windows, it looks a lot nicer. There are tf2 prop zoo maps floating around this website somewhere.
-Move your lights away from the floor and more towards the ceiling and seriously give them some love as right now they are just blobs
Overall
-Your environment lighting is bland at best and leaves a lot to be desired, try messing with the color and brightness settings.
-Use fog but make sure the color matches the 2d skybox so you dont get that awful ghosting you see in amateur maps.
-Youll need more lighting besides the environment light to guide players through the level
-You have zero height variation in your first shot and I am assuming the rest of your level. Add some stuff in the background to break up the monotony.
-This will need a lot of polish to look good so...
Work on your gameplay first then come back to the styling.