On the topic of texturing, you might find it worthwhile to make your dev textures easier to read. The finished map will most likely have contrasting colors between walls and floors, making it easy to see the contours of geometry. You can imitate that without just fully texturing the map by using varying dev textures, like greys for floors and white/red/blue for walls. It takes some more time than just texturing everything the same, but a nicer looking alpha will get you better feedback.
My main concern is with the layout. The map appears to be almost (if not exactly) symmetrical in 2 axis, meaning that when leaving spawn, the left and right paths lead to areas that function identically.
TF2 relies on creating multiple paths through an area not just so that players can avoid firefights and not be funneled into a single area, but also so that the map can have variety in what areas work best for certain classes. While having two identical areas doesn't mean that classes don't have an area that "works" for them, I would argue that it's always a less interesting design than one that makes the areas different. Without having any idea of which teammates/enemies are already in either area, players have no reason to pick one over the other.
Again, I don't know that this kind of design is inherently flawed, but it does make your map more generic, and I don't think TF2 does well with generic gameplay spaces. (Other games do! Halo 2 had deathmatch maps that were symmetrical on 2 axis and they played pretty well.)
The map is also very wide, which may make it difficult for teams to have a structured push/pull over the point, since players can flank the enemy team quite handily. Wide KotH points aren't inherently bad, but I think the ones that work best (Lakeside!) try to segment the middle axis space into multiple sections so that fighting happens mostly between the team sides of the map instead of the left and right.
On a positive note, I dig the setting. The new Doom did a really good job of making a sci-fi setting that isn't washed out in greys, and replicating that in TF2 is a good fit.
Good luck!