'In the games of madness' discussions and FG in general

[Radiance]

Having the weapon/ammo be scarce only partially solves the problem while introducing another one. If the weapon is fully available, then sure, it's less of a horror game and more of a slightly-scarier-than-usual action game. But forcing the player to look around and gather the weapons/ammo just turns the horror into a collection game.

This is already in all inventory based games but it does not have to be heavy distraction for the player. More like of the choice.
In Amnesia and Outlast if you run out of oil or batteries, the game provided it for you along the main story line and it was not actually a big deal to play without it.

It's like when horror games have the "fill your flashlight with batteries" mechanic. It's annoying, and it ends up with either the player running out and having to scavenge around in the dark or with them having so many batteries that they may as well not even have the collection mechanic - either there are so few that the game becomes arbitrarily difficult, or there are so many that the mechanic becomes redundant. This is an issue of balance, sure, but the balance is largely dependent on the player's own pace, and short of virtually railroading the entire game, it's virtually impossible to balance a collection mechanic like this based around the player's own personal pace.

I would set mechanic as the player's choice. So, if he doesn't like to do something in the game, it would affect his gameplay in another way.
Gameplay should be modular and adjustable by the player to some extent.
I brought up weapon mechanics just to have additional playstyle variety.
There could be some other mechanic what was introduced in System shock 2, or even something completely new we haven't seen yet.

Personally, I think that with this style of horror games, the less that the player can actually do, the better (to an extent, of course). The more options the player has, the less scared they become, which is counterproductive for a horror game.

I think otherwise.

If for example, the level layout of SOMA was similar to that of a game like Dishonored, players would find a safe location to scout out the level and plan the most effective plan of attack (figure of speech). Once they have a strategy, they are much more confident in how they proceed, which undermines the intended atmosphere.

Secret strategies can be discovered by the player but they could come with a challenge so that they don't feel like safe point. Player gets a reward for finding out how to cheese the A.I. but with a twist of fortune with aftermath in the storyline, possibly.

For an atmospheric horror game, the players are meant to try and inch their way forward, desperately trying not to attract the attention of monsters, while they try and figure out what the hell they are going to do next.

But that would leave the game to linear and with no exploration. Personally, exploration gives a sense of atmospheric immersion.

If anything allows the player to temporarily stun or wound the monster, it should be an option presented to them in the moment, like turning on the electricity while the monster is standing in a puddle, or hit the spotlights if the monster is used to living in the dark. This promotes more of an in the moment feel, and the player is rewarded for using their ingenuity and their surroundings to get out of a hairy situation. But if the player just has a "Press A to not die" mechanic whenever they feel like it, then encounters lose much of their intensity, and the game gets boring.

Yes, environment hacks and puzzles are welcomed. Basically, everything what can engage the player into thinking how to approach the problem he's facing.
And, so that he does not have only one option for solving his endevours (for the replayability).

You tried UNBIRTH?

No, I haven't.