What can the reader infer about Montresor’s social position and character from hints in the text of "The Cask of Amontillado"?

In the classic tale of revenge and horror "The Cask of Amontillado" by Edgar Allen Poe, the narrator Montresor lures his victim Fortunato, who has committed some sort of real or imagined wrong against him, into the dark catacombs, where he leaves him chained there in an underground tomb.
The story's text carries numerous hints that Montresor's social position is that of a privileged person, a rich man, and a nobleman. For instance, Montresor says that he collects wines. He writes: "I was skillful in the Italian vintages myself, and bought largely whenever I could." He is wealthy enough to have attendants at his home, and he orders them to remain there in his absence, although he knows they will disobey. He speaks of walking through several suites of rooms before arriving at the entrance to the underground vaults, indicating that the house is quite large. It's evident that he is a nobleman because he has catacombs under his house that he refers to as "the catacombs of the Montresors." Only aristocratic families would have private catacombs that hold the remains of their ancestors.
While they are underground, Montresor also tells Fortunato that the Montresors were a great and numerous family. They have their own coat of arms, which is another indication of aristocracy. "A huge human foot d'or, in a field azure; the foot crushes a serpent rampant whose fangs are embedded in the heel."
As for Montresor's character, he is obviously psychotic and deranged. He leads his companion into the catacombs, buries him alive, and manifests no remorse for what he has done. The only motivation he gives for the gruesome murder is found in the first sentence: "When he ventured upon insult I vowed revenge." He pretends to be a cheerful friend while using the cask of Amontillado as bait to lure Fortunato to his death. He makes it clear that he contemplated the deed and planned it out long before the execution.
His sinister and devious character is also evident in the way that he pretends to try to convince Fortunato to leave the vaults when he begins to cough, knowing that he will not agree. Finally, after Montresor chains Fortunato in his dungeon and begins to brick up the entrance, instead of feeling any compassion, he mocks Fortunato's pleas for mercy. Montresor writes: "My heart grew sick; it was the dampness of the catacombs that made it so." In other words, if he feels any remorse at all, he covers it up by attributing it to his surroundings and not to his emotions.