1)
What is the connection of judging be'Emes and his throne being established forever?
1.
Malbim: The king's throne is based on Mishpat - "Hen l'Tzedek Yimloch Melech" (Yeshayah 32:1). Sometimes there is a fraudulent Din, and the king must investigate to find the Emes. Then, his throne will be established forever, just like Emes is one of the eternal matters.