I think the centerpiece is too hard to access. There's only one normal path and it's very out of the way. I was thinking a ramp like one of these would work well.
I also think that this roof spot could use another way up. Maybe some props to jump on.
Finally, the sniper window near spawn covers too much area, and is very hard for any class other than another sniper to attack. Even if an enemy manages to get to that spot from inside, it's still right next to spawn. I suggest just removing it altogether.