I have found a doorway that has red slats, like an air vent. It says use crush to open when I get close enough. None of the weapons I have make any impact on it. How do you get through this obstacle?
Crush is an ability that you unlock as part of the character skill tree. You will get points when you level up to spend on these. You will need to spend a point on the crush ability If you have not done so already.
To use crush on a door, simply sprint into it. Just like you would with any of the red crates. You will burst through the red grated and get through to the other side.