These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Hell Is That Noise: In "Compilation". Arron and Nick have just finished recording "SA Vlog #1" and Nick is having doubts about the vlog. They talk for about a minute, then OH MY GOD WHY IS IT SO LOUD
Jerkass Woobie: Arron may have had the best of intentions when uploading his videos of Nick to the channel, but maybe he should have gotten consent from Nick before showing his most private and vulnerable moments to the world.
And it's unlikely that a psychologist would use the videos anyway if Nick were to seek help. If Arron couldn't see the clips where Slendy appears, how would the psychologist know if the videos were edited or not?
Nick: Well, there are some people who don't like to enjoy things.
Paranoia Fuel: As we saw in "seeing me again", the guy in the jumpsuit was watching the whole time as Nick and Arron filmed their first vlog.
The Woobie: Arron is this in spades. He takes in his friend, only for him to become distant and hostile. Then he tries to get him to seek help, so he runs away. And THEN there are videos posted to his account showing that whatever was watching Nick has affected at least one more person. He hasn't heard from Nick in a month.
Nick is this as well. His parents are suddenly taken away from him in a car crash, stuck in the hospital. The his friend has him start a vlog and pretty much makes him reveal his issues to the world. Lord knows what else was going on in his mind, as we saw in "Addendum".