First Stage:
-The blu respawn should really have a sliding door between the two ramps. This is to avoid getting killed after respawning, as when the grates are opened projectiles and bullets can reach the respawn area.
-Grates should open more slowly.
-Remember to parent the resupply locker to the func_regenerate entity.
Second Stage:
-The second point needs to have more structures, as this would improve the whole look of the place. Right now this area is way too plain.
Third Stage:
-Besides from making the upper entrance to the second point safer from snipers, which you already did, its still easy for demonmen to block both exits. You should really make an alternate path.
Regards,
Fede