1)
What is "Oz"?
1.
Radak: It is Torah - "Yachazek b'Ma'uzi" (Yeshayah 27:5).
2.
Radak #1: It is salvation from damage due to thunder, lightning and noise.
3.
Radak #2: [It is strength;] He will humble all nations in front of Yisrael. Malbim - evil will not touch Yisrael; they will get strength.
2)
What is the Brachah of Shalom?
1.
Radak: They will never have war.
2.
Malbim: The Resha'im who fought with Yisrael will be destroyed; Yisrael will have Shalom from afflicters.