What do we learn from "la'Kol"?
Radak: He is good and merciful even to Chayos, Behemos and birds. Man should go in His ways, and destroy them only for a need, or to avoid damage from them.
Malbim: He is unlike a person, who is good only to his servants, and avenges 1 and hates those who rebel against him. Hashem is good even to Resha'im, and thinks how to make them repent 2 .
It says "Kel Nekamos Hashem"! However, since Heshem strives to help them repent, this shows that he loves them, and hates only the evil in them. (PF)
Sanhedrin 102a: He offered to Yaravam to repent. He dug a tunnel under Kisei ha'Kavod to enable Menasheh to repent (Yerushalmi Sanhedrin 10:2). He sent Yonah to cause Ninveh to repent. (PF)
What do we learn from "v'Rachamav Al Kol Ma'asav"?
Radak citing Bava Metzi'a 85a: Rebbi's slave was cleaning the house; she was about to clear out some baby rats. Rebbi stopped her, for "v'Rachamav Al Kol Ma'asav" (and we should go in His ways).
Brachos 7a: A certain heretic used to annoy R. Yehoshua ben Levi. R. Yehoshua ben Levi planned to curse him at the moment of Hashem's anger. At the moment, he fell asleep; he realized that Hashem did not want him to curse him, for "v'Rachamav Al Kol Ma'asav."
Malbim: He does not want His creations to be destroyed; He thinks how to prevent a person from being totally cast off.