The following is thinking further on the issue, not necessarily disagreement with your points:
Your comment is close to advocating compartmentalisation for mental health: the deliberate choice to have a known bad map. Compartmentalisation is an intellectual sin, because reality is all of a piece.
We can't go to absolutes. Historically, "someone warned me off this information" has been badly counterproductive. Lying to oneself about the world is bad; a society lying to itself about the world has historically been disastrous.
How much science has exploded people's heads as if they'd seen a very small basilisk? Quite a lot.
That said, decompartmentalising too quickly can lead to decompartmentalising toxic waste, which can lead to problems. Humans are apes with all manner of evolved holes in their thinking.
What I'm saying is that even though dangerous stuff is dangerous, a programme for learning to handle it strikes me as really not optional.
(And this is not to say anything about my opinion of Suicide Note, the fat rambling book-length PDF this post is about, which I dipped into at random and rapidly consigned to the mental circular file. I'd think anyone susceptible to this one is already on the edge and could be pushed over by anything whatsoever. I realise I'm typical-minding there, of course.)
We can't go to absolutes. Historically, "someone warned me off this information" has been badly counterproductive.
There are lots of warnings about information that's supposedly wrong, or confusing, but these are relatively easy information hazards to defend against. If the only danger of a text is that it's wrong, then being told why it's wrong is sufficient protection to read it. Highly confused/confusing text is a little more dangerous - reading lots of postmodernism would be bad for you - but the danger there is only in trying to make sense...
My various interweb browsings stumbled me upon a potential Cockatrice in written, philisophical form. I've thus far read through the first chapter, and it is less anti-rational than most philosophical writings.
I'm reading through it right now, and will provide my feedback when I'm done, likely as a front-page post.
Personally, I'm a Fatalist, with some sort of Weird Soldier Ethic, who plans to go out the same way that Hunter did (if the cops don't get me first), but I've got a bunch of nonsense to Write first. I figure that'll make me somewhat immune. That aside, I doubt it's a real cockatrice - or we would've heard about it before.
It is a strong exercise in Nihilism. So, with those cautions given, I offer it to you: an extensive suicide letter.
Tip of the hat to this guy.