What are the strategies to getting past a stationary guard that is watching the door?

So in my last game, the teleporter room's door was watched by stationary guard. The door itself from my side has squares on left and right of it blocked. So when I open the door I:

• Immediately visible, and
• Cannot hide after being seen

Given that this was the teleporter room I solved that by getting one agent KOed which lured the guard out, and then ambushing the guard with another agent. The agent that remained up then dragged the KOed agent to the teleporter.

Questions:

• Are there a way to get past these without getting KOed? For teleporter room getting KOed works because you are almost done, but if this is a starting room you might need to think of something else. What would that be?
• What are the penalties for leaving an agent behind? That is if I do not drag it to the teleporter?
• Is guard placement mostly random, to the point where you really can have a guard watching the single starting room door all the time? I have not seen this so maybe the game makes sure to only do this when being KOed is a viable option?