1)
What is the meaning of "b'Fesha Eretz Rabim Sareha"?
1.
Rashi: This is punishment for the land, when its many officers pursue their unjust gain.
2.
Malbim: Sometimes a land rebels against its king, and they intend to cast off the yoke of one man, via this many tyrannical officers arise, and all rule over and pressure the land.
2)
Why does it say "uv'Adam Mevin Yode'a Ken Ya'arich"?
1.
Rashi: Due to a person who understands, punishment is delayed from coming.
2.
Malbim: If there is one who understands the foundations of Tzedek, and he can stop the rebellion, he will bring a cure to this illness.