1)
Why did Hashem become angry?
1.
Malbim: The king was a Rasha ben Rasha; in such a case, Hashem punishes the sons for the fathers' sins. 1
1
I do not understand why the nation is punished because the king is a Rasha ben Rasha. (PF)
2)
Why does it say that Hashem put them under Aram "Kol ha'Yamim"? Verse 5 says that Hashem saved them from under Aram!
1.
Malbim: Hashem decreed that they will be under Chaza'el and his son Ben Hadad "Kol ha'Yamim", i.e. all the days of Chaza'el and Hadad. Surely he told them this via a Navi.