Ok maybe where I am going is back in the direction of "examples.". Is protecting oneself from a murderer something that comes under the heading of " justice " at all?
I think most pple today would say that it does. Are you saying Epicurus would not (say that self-protection involving harm to the aggressor) because that does not fall under the category of justice?
To the first question:
Yes.
You are protecting yourself from being harmed. I believe Epicurus would say, if possible, make decisions that don't put yourself in a situation in which you can be harmed. But, if chance does put you there, it is natural for you to not want to be harmed.
Eschewing the word "justice", I would fall back on δίκαιος's sense of "civilized behavior." Self-defense is justified under "Neither βλάπτειν nor βλάπτεσθαι."
I guess that also sort of addresses question #2.