Carlo understands from various factors that it was Nusco who killed Xenia years earlier and that is why Sfera wants him dead: he paid for a crime he did not commit. And Muzo and Marta were punished by depriving them of their dearest affections for not believing him.
A religion is a belief system with rituals. The missionary kopimistsamfundet is a religious group centered in Sweden who believe that copying and the sharing of information is the best and most beautiful that is. To have your information copied is a token of appreciation, that someone think you have done something good.