Why does it say "Kedosh Yisrael Moshi'echa"?
Radak: I am the Kadosh of Yisrael your father, and I save you.
Malbim: "Ani Hashem Elokecha" corresponds to natural salvation (refer to 43:2:1:2). He supervises that evil not touch you. Kedosh Yisrael corresponds to supernatural salvation; I save you miraculously.
What is the meaning of "Nasati Chafrecha Mitzrayim"?
Rashi: They were a redemption for you. Their firstborns died, and you, Bni Bechori, were saved. You deserved to be eradicated - "v'Amar Lishpoch Chamasi Aleihem
Malbim: Sancheriv totally exiled Kush, but he took only captives from Egypt.
Why does it mention "Seva"? Is it not included in Kush (the father of Seva)?
Radak (according to Kli Paz): Kush includes the other sons of Kush.