1)
Why does it say "Ga'alta bi'Zero'a Amecha"?
1.
Radak: You did not redeem Your nation with the consent of their subjugators, rather, via great force and an outstretched arm.
2.
Malbim: The purpose of the wonders is for us, and not for Hashem's perfection. Therefore, since I am ill, and my hand drips, and I am not worthy to receive miracles, Hashem will not lift His right hand to do wonders.
2)
Why does it say "Bnei Yakov v'Yosef"?
1.
Radak: [Bnei Yakov] descended to Egypt due to Yosef, and Yosef financed them his entire life, as if they were his children.
