This level’s really coming together. I think if you turned on Ambient Occlusion or baked it into the lightmap that would really tie everything together, I rely on that a lot in my game. Also look up how the Quake community does trimsheets (especially the Makkon ones). It’s a lot of fiddling around with UVs to apply them but the results are amazing.
Reminds me a bit of The Citadel, just less horny because the bad guys are coomers instead of the dev. I think you’re on the right track, keep it up.