1)
What do we learn from "b'Kum Resha'im Yisaser Adam"?
1.
Malbim: When Resha'im rise to rule, one who is an Adam, he hides, for people deny Hashgachah and abandon Hashem's way, and they resemble animals. A Tzadik must hide himself due to those who mock and pursue him.
2)
Why does it say "uv'Avdam Yirbu Tzadikim"?
1.
Malbim: When [the Resha'im] perish afterwards, all recognize Hashem's Hashgachah and punishment, and via this Tzadikim will increase.