Do you think pt 2 deliberately preserves the ambiguity and ethical standing of Joel, or does it attempt to highlight him as a unique outlier of violence and self-centeredness?
I find that there are two typical main camps of interpretations (this is a simplification/generalization).
The first camp typically involves those who view Joel as more ethically compromised than most if not everyone else across the stories. Many would describe him as a thug or even a monster. Perhaps cited examples would be that Joel was a hunter, and claims that he "killed a lot of innocent people". Or Ellie's anger directed towards him.
The second camp consists of those who believe Joel isn't any more or less ethically compromised than anyone else i.e. the Fireflies, Abby, etc. Many would describe his actions as human. Cited examples may include Ellie's forgiveness or the people of Jackson looking up to him. And that Ellie's anger wasn't meant to be taken literally at face value.