That well may be the case but FPSC is not most games and cuts out unecessary content wherever possible.
To have a door open two ways you need twice as many animation frames.
I have not actiualy checked the swinging door models in FPSC to see how the animations are set up, but they probably do both open and close - this is bourne out by the script which opens a door and then closes it again. One of them does so you should be able to take a default script and edit it appropriately to make a door open and close and also keep the collision on at all times. As said the engine may not like this but it culd probably be done as a test - if no problems are encountered then you could keep your new door script set as you like it and not as the default one(s)
You can have a default door open away from you in FPSC but as in real life a door that has a frame and door stop cannot swing both ways - the door jam prevents this - its normal that a door opens into a room so by rotating the positional arrow in editor when placing the door on editor you should be able to have the door swing one way or the other, or open and close but not inward or outwards both ways without a relative script by which means you could effectively achieve what you want. Again if you want the collision on always then you will have to switch it on permanently in script.
Remember though that having collision set to on when the door is in the open position is going to make it almost impossible for enemies to get through the door if approaching from anywhere near the behind open door position as they would get stuck on it. AI brains and object avoidance rotines in FPSC are poor so dont expect an enemy to realise the door is open and in its way - you are asking to much there. They may be able to follow the player if the trajectory away from the open door gives them enough room, but as said dont expect them to avoid the open door - they just wont know its open until they hit it and then wont know how to get around it. V1 collision for enemies is worse than EA and I dont give them much chance of avoiding an open door with collision on successfully unless approaching from the free side.