I tweaked it a bit because this seemed more dynamic to me

What are the full details of his poisoning one of their fellow passengers?

Being a smart aleck and defining details of the poisoning as specifically the part with the poisoning: the passenger (Arthur) had been harassing his canonmate, which is why Walter hates the "cult" so much. Arthur can also turn into a tiger. Hence, Walter needed to be dishonorable with total surprise

However he was truly a tool using a paralysis needle he had no means of testing, which was (according to the memory share) apparently more of living death needle. For the record though after that, Arthur was fine, the poison wasn't like an emetic or anything

Actual full details: the reason he was so convinced that attacking the guy and presenting proof would cheer her back up from the bullying is because she was supposed to eat it.

* Arthur was hurt from the actual attack part. He is still not completely fine. That part meant to refer to the drug itself not having a long term poison esque effect

"Would really rather die than graduate?"

Graduate as in go home instantly, though technically extending The Suffering Machine: sure
Graduate as in be a good person who doesn't do crimes: better than dying though probably some major downsides (jail)
Graduate as in he develops into the kind of person who would strangle monster Misty with his bare hands for the greater good: would genuinely rather die

Many wardens didn't strangle Monster Misty, bud.

Trevor, ulla, Hilbert, Will... They all gave up what used to be the most important to them

for healthier things that became more important because they realized they can have that.

"healthy choices" aren't very Dostoevskian

pyotr is allergic

he will literally throw up if presented with a healthy choice

For complicity and not caring who their inmates hurt

In fairness to Hilbert, Hilbert didn't care who he hurt either.

Will and Ulla absolutely care about that.

and he's not getting in the middle of your weird Trevor love-hate on.

in all seriousness, I wouldn't make Pyotr be healthy to graduate

he has to become a second different type of evil guy instead <3

You'll be doing it the way Dostoevsky would have wanted it.

pyotr becomes a c*tholic!