1)
What is the meaning of "u'Vakosi"?
1.
Rashi: I will empty. This is like "Bukah u'Mevukah" (Nachum 2:11) [Radak - and "Bokek ha'Aretz" (Yeshayah 24:1)]. He used this expression because it is similar to Bakbuk that He discussed. Malbim - it is called Bakbuk because it is made to empty out its contents. So I will empty the counsel of Yehudah.
2.
Radak citing Targum Yonasan: I will ruin.
