These instances give me the indication of being trolled lol.

Most important when dealing with the alien is to NEVER give in to your desire to hide for too long. The longer you hide or sneak around an area the closer the alien gets to finding you. This goes double on higher difficulties. If the alien isn't in your line of sight you should be walking upright because it's much faster than sneaking but just as quiet. Sure it will get you seen faster if the alien looks your way but if you hear the alien that close to you it's easy to duck down behind something to break line of sight again.

The Alien picks the distraction closest to it. So if you throw a noisemaker further from the Alien than you are, it will notice you first. The AI is actually working perfectly. It’s not ignoring the noisemaker, it’s prioritizing its target.

It ignored the noisemaker because of the difficulty and because you were walking not sneaking. It heard you.

I can't really agree with your analysis. I finished this game on hard and nightmare, and the game doesn't really cheat. It wants you to play by it's rules. For example, if you use multiple cover types, you will feel that you are the one tricking the alien. Staying always on the move even if circling covers such as boxes or couches allows you to get very close to the alien and escape it. Nightmare made me choose lockers as a last resort as I wanted to keep the alien in sight. Always stay crouched, as simple steps on higher difficulties will register as sound like how you were spotted with its back to you. Minimize the motion tracker due to its noise and find routes using your own senses. Sure sometimes it can go haywire but not because of cheating but rather because how all these nodes may not work perfectly in a situation. You can then accept death with a smile or do a random action to balance the AI and get it back to its normal stance. But this game is really hard and the atmosphere will suck you in and add a sense of dread even if the alien wasn't there so you do need a mindset to play it and it is not for everyone.

19:20 In each of these examples, you exit crouch and start walking while still near the Alien. He simply hears it and starts running to the last location he heard a footstep. That's what kept killing you.

I like to think of those moments when distractions fail as moments when the alien is basically just like: “Really? You thought I’d fall for that?”

19:39 no, its because you stood up and started walking, creating a louder noise compared to you crouchwalking

20:20 “inconsistent reaction” brother you did two different things. You started walking in the first clip, causing the alien to hear you and change focus, and in the second clip you kept crouching. Not really sure what you’re expecting when you do two different things…

"more like an intentional, unpredictable and malicious glitch in the system to be avoided at all costs."

My gosh. I totally misread that thumbnail. I was like, "Okay. That's odd. But I'm listening."