I like C intensely, although, as booj said, the gameplay is quite different, with the deathpit almost impossible to fall into. Maybe show us a different angle of C? Also, the upper floor is changed beyond belief, and although it looks FANTASTIC, I think the gameplay will end up being quite different. Good use of the nucleus dish, though in the upper area, there is some texture tiling (maybe its just my highly trained mapping eye)
I personally don't think you have all too much red. Its a red point, it should be red, no? The only thing about the lighting that could change is make the lights a bit less red, and just let the walls be the source of the color.
B, is meh to me. I dont like the shape of the control point building. Its shaped like a hut, where the rest of your buildings are industrial. Great job pulling off the industry theme, though. However, I prefer your rainy desert theme around A.
I wish that there could be more desert than industry, since that part of the theme is just so cool. I love how you made curbs. If there is one thing every tf2 map is missing, it is curbs. IDK why. Around A, I still wish there was more desert. I like how its an obvious loading dock, so it does have a reason to exist.
Around the Blue spawn, its great, loving the desert, though, it makes no sense to me why Blu would have such a large (tall) building in the middle of nowhere, next to a red facility.
In all, great job, but there are still some problems.