Who are "Rosheha"?
Radak: They are the kings, or the Sanhedrin.
Why does it specify the Kohanim?
Radak: They should have taught the Torah ? "Yoru Mishpatecha l'Yakov" (Devarim 33:10).
What is the meaning of "bi'Mchir Yoru"?
Radak: One who gives to him money, he rules like the giver desires. Malbim ? this is in rulings of Tum'ah and Taharah, Isur v'Heter.
Which Nevi'im are discussed?
Radak: The false Nevi'im. Their Nevu'ah is Sheker and divination, like I explained (6).
How do they rely on Hashem?
Radak: They say, since the Shechinah is among us, evil will not befall us. He will not destroy His house! This is like they said "Heichal Hashem Heichal Hashem Heichal Hashem" (Yirmeyah 7:4).
Malbim: Refer to 3:10:1:3.