What is the significance of the Chasid being lost?
Malbim: It is one who deeds are more than is required, both in Mitzvos Bein Adam la'Makom and Bein Adam l'Chavero. He is compared to a cluster full of grapes. So the Chasid is full of fruits of Tzedakah and Mishpat. Chazal said (Sotah 47b), Eshkol is a man that all is in him.
What is the meaning of "Yashar ba'Adam Ayin"?
Rashi: There is no straight person amidst the people.
Radak (1): Refer to 7:1:4:1.
Malbim: This corresponds to "Bikurah Ivesah Nafshi" (1) ? one who does what is straight ba'Adam - Bein Adam l'Chavero. Also this is lost. Only Michah remains 1 .
Why does it say "Yatzudu Cherem"?
Rashi: They trap with their nets and traps. Radak - this is like "Mishtach Charamim Tihyeh" (Yechezkel 26:5), "Metzudaim va'Charamim" (Koheles 7:26). Everyone traps his brother to kill him, like a hunter traps birds with a net.