dimitri is a super boss that lets you skip most of the grind of the scenario, youre supposed to make him cum on the turns he's gonna use the instant loss attack (and handcuffs also work for one of them)
i think you turn the screws on the vent with the debit card
you use the chalice to weigh down the trap with the stone tablet to let you out of the room which locks and floods with gas after taking the tablet