How does enemy door breaching work?

Intro

During one mission where I was supposed to free a captured agent, I attracted the attention of a captain guard in the next room by opening the door in his vision, then quickly closing it again. Thinking that I was going to be clever, I had my agent place a shock trap on the door, and had her wait right behind it for the captain to walk right into my trap.

I was unpleasantly surprised then, when the captain walked right up to the closed door, announced that he was going to breach(!) it, and then completely blew the door up right in my agent's face, knocking her out for a couple of turns! The breach action seemed to disable the shock trap too, so that the captain guard was completely unaffected.

Questions

1. How does enemy door breaching work in Invisible Inc? I know that if an agent is standing behind a breached door, then they'll be knocked out for a certain number of turns (two turns?), but what if they're just standing 1 tile to the side of a breached door?
2. Does breaching a door always disable any traps placed on the door, like a shock trap?
3. Which enemies are able to breach doors? I know for sure captain-type guards are able to, but are there others?
4. When do enemies breach closed doors? When they're just suspicious (yellow question mark), or only when they're alerted and actively hunting you (red exclamation point)?

Solution 1:

This comes down to the differences in guard behaviour when in "investigating" and "hunting" modes.

A guard who is investigating with a yellow question mark above their head will open the door normally. If they are actively hunting with a red exclamation mark above their head then they will breach the door. This is where they kick in the door which will KO anyone standing immediately to the side.

For this reason it is advisable to stand your agents to one side of the door, this also allows them to walk through the door before you KO them so you pull them into cover.

Solution 2:

Regular Security Guards

So I just played a mission where a regular guard (not a captain) used a "Door Slam" which seems to work like a breach. Just like with a breach, the guard ended up knocking out an agent who was hiding behind the door for 1 turn.

The guard was alerted and hunting at the time. I don't know the exact specifics of the conditions under which a guard will use Door Slam however.

Akuma Drones

After hacking an Akuma drone, I discovered that it also has a "Break Door" ability, which costs 1 AP, though I'm not exactly sure what the ability can do besides "breaking" doors.