Why does it say "Ki Sa'aleh Vavel ha'Shamayim"?
Radak: Even if it will build great buildings, and fortified in Shamayim, it will not help. To strengthen and fortify on high will not help, for its plunderers will come from Me. Refer to 51:53:3:2.
Malbim: Even if Bavel would be in a good situation based on the Ma'arachah, I will be Shoded the Ma'arachah [override it, to make Bavel fall].
What is the meaning of "Sevatzer"?
Rashi: It is an expression of a strong Mivtzar (fortress). Radak - this is like "Gedolos u'Vetzuros" (Devarim 1:28), and "Levatzer ha'Chomah" (Yeshayah 22:10).
Why does it say "me'Iti Yavo'u Shodedim Lah"?
Rashi: The plunderers will come from Me, from Shamayim, from higher than [Bavel].
Radak: I aroused the spirit of Daryavesh and Koresh to come to Bavel.
Malbim: Refer to 51:53:1:2.
