What is Montresor's attitude toward revenge, or punishment in "The Cask of Amontillado"?

It is apparent that Montresor feels revenge is justifiable when insults and injuries go beyond the pale [outside the boundaries of normal behavior].

Poe's unreliable narrator explains to his audience that he has endured multiple injuries until the point that they become so excessive—"a thousand injuries"—as well as compounded with "insult" that he feels compelled and justified to avenge himself. Nevertheless, there are certain stipulations for seeking true revenge:

1. The act of revenge must punish, and it must punish without any risk to the avenger. (In his act of luring Fortunato into the catacombs, Montresor takes no risk as he commits this act during the Carnival in which people are distracted in their celebrations; furthermore, Fortunato is disguised by his costume.)


2. The revenge must "punish with impunity." There must be no consequences that result from this act of retribution. (Apparently, there have been no consequences for Montresor since it has "half a century" and "no mortal has disturbed" the remains of Fortunato.)


3. The avenger must not himself be the recipient of any retribution for his act. (Montresor has received no punishment for his crime. No one has avenged Fortunato's death against him, either.)


4. The revenge is not accomplished if the victim is not aware of the identity of the avenger. (Fortunato certainly has known that he was being walled in to die by Montresor.)