So if you are at the lighthouse with the low chaos rating, you will encounter havelock while he is talking to himself very desperatly it seems.
it appears that pendleton and martin are also in the room but the game handles them as they were dead.
now to my question: are they actually dead, poisoned by havelock? it wouldnt make much sense because havelock would need them to become succesfull in his role of the new lord regent.
or are they just passed out from drinking too much?

They are poisoned. If you listen to him talk, he kind of explains it. He's tired, they tried to do the right thing but in the end they all got corrupted with power and started fighting so he eliminated them.

You know, I can almost forgive him, and it looks like so did Emily.

Maybe he can redeem himself by serving loyally as the empresses admiral. That's what he's good at.

I wanted to give him a second chance as well, but the moment I snatched the key he just went ape[censored] and I had to kill him. Besides, that kill animation where you stab him in the hand and then make him shoot himself in the face is well worth it

I think it's a bug. Sometimes the same thing happens to me, other times he lets me take the key without fighting back.

I took the key aswell, and he went insane for me too. So I threw a springrazor in his face and walked calmly for the door.

By the way if you peek in the keyhole on emilys room you can clearly see a HUGE bloodsplatter on her floor. Did Havelock beat Emily? Did she start to have her period? Or did Havelock... molest her?

I think that is a bug, because in a high chaos ending you can follow the blood and you find a maid. Whom I assume was trying to protect Emily.

I took the key, and he attacked me.

I was going to let him live, but...Well, that awesome execution scene made it hard for me to regret it too much.