What unsettles you most in a CS?

[FrictionalWeekly]

I'm usually looking for ways to make my custom stories more fun, dynamic and unsettling.

To make things more simplistic and statistical, I've set up a question format so that I don't have to ask you things in long paragraphs and I can get an answer for each question.

What scares you in general?:

What scares you in a custom story usually? New monsters, lights going out, etc:

What tactics best scare you in horror games? Having a happy mood and very slowly getting darker for example:

Do monsters in Amnesia mods scare you anymore? Even if they are custom?:

Are you used to Amnesia music and Penumbra music to where it no longer unsettles you?:

Would breaking the 4th wall be creepy or instead end up being silly?:

What part of a cs unsettles you most? Story? Gameplay? Ambiance?:

What bothers you most in a cs? (Pointless rooms or too many resources for example):

Do you like a long cs that has fairly simplistic puzzles?:

If there's one cs that gave/could give you nightmares, which one would it be?:

Last and not least, what tips do you have for me on modding and how to unsettle the player?