1)
Was Tzidkiyah truly a Rasha?
1.
Malbim (here and Melachim II, 24:19, from Sanhedrin 103a): He was a Tzadik; his generation were Resha'im. Divrei ha'Yamim II, 36:12-13 says that his [only] Aveiros were not humbling himself in front of Yirmeyah, and rebelling against Nebuchadnetzar 1 . It says "like all that Yehoyakim did", for also he did these two matters.
2.
Midrash Tanchuma (Vayetzei 4): Yes.
1
The Gemara said also that he did not protest against his generation. (PF)
