1)
Why should they flee the Kasdim?
1.
Radak: This is not fleeing amidst fear, for they will leave high-handedly and singing! Rather, "Birchu" teaches that they will go rapidly. The same applies to "Livro'ach Tarshishah", "Ki mi'Lifnei Hashem Hu Bore'ach" (Yonah 1:3, 10). So my father explained.
2)
Why does it say "Hotzi'uha"?
1.
Radak: This is the tidings.
3)
Why does it say "Ad Ketzei ha'Aretz"?
1.
Malbim: You can tell this publicly, throughout all of Bavel, for the Ge'ulah from Bavel will surely come.
4)
Why does it say "Ga'al Hashem Avdo Yakov"?
1.
Mahari: This is not Koresh's deed; it is Hashem's.