פירוש על עמוס 2:4

And after speaking of the nations, the destruction of Judah is mentioned because they were also guilty of the sins of the idolatry, immorality and murder. And their fourth sin was their rejection of the Torah and its laws. It wasn't that they merely served idols but they also did not serve Gd and therefore they rejected the Torah and did not keep it's lawas and they followed the falsehoods of their fathers, meaing the Baal that they served and the false prophets that they obeyed. And therefore Gd decreed that a fire would come to Judah and that is the sword of Nevuchadnezer who defeated them and exiled them. And the simple meaning of the fire is that which burned the palaces of Jerusalem and the fire that burned the Beis Hamikdash.

And I will explain what the 3 sins that are mentioned 8 times in Amos propechies that refer to idolatry, immorality and murder. That every nation committed these with reprecussions only being punished for their actions regarding Israel. The reason these six nations are mentioned is because they are close to Jerusalem and other nations who acted wickedly towards each other aren't mentioend here becasue they did cause Israel harm . And Judah who is mentioend here also implicates Israel through its actions and is therefore mentioned before the prophecy about Israel. And this answers the 3, 4, and 5 questions.