Visually, that map looks great. A few pointers, however:
The skybox, though it looks very nice, looks too realistic for tf2's painterly style. You should request (or make) a version of that same thing, but with a much more painted look, like the other skyboxes. You also seem to have used a few HL2 textures in the last screenshot. To filter the material browser to only include tf2 textures, type "tf" into the keywords bar. You should be able to find a good equivalent to the window textures you've used there.
Have you tested this, by the way?