-Door must be destroyed to get to the dirty bomb/vacceine lab.
This one is fine. It works and provides an excellent incentive to blow/repair as it acts as a great choke point. For the attacking team, it ACTUALLY WORKS as a shortcut. Good design plan, and good implementation.
-Side stairs.
No. Bad idea.
-Side door
Wow. No.
Let me clarify. I know this shortcut was built to let Lights get above it, but the design doesn't work. If you are Light body and you get over the door, you will be killed by the enemies, as thats their spawn route. Even if you aren't, and all the guys are at the door, you won't have any good weapons to sneak up behind them without being spotted, and do damage. Stick with the charge on the wall.
Aquarium:
-Lift
Maybe I'm dead wrong, but I don't think anyone uses this.
I can't properly critique the Shipyard ones, since I haven't played that map yet.
Please add more below!