1. There are many difficulties. "Xishan bandits and bandits must not invade each other" echoes this.
2. The main content is to praise the mountains and rivers of the motherland, recall the national history, discuss the world situation, and satirize the current emperor. It expresses the author's empty heart to help the world and his concern for the country and the people as he has no way to devote himself.
(As long as the meaning is correct)