1)
What is "ha'Nosen ba'Yam Derech"?
1.
Rashi: He makes a path in the Yam Suf. Radak - the One who did so for Amo Yisrael, He will save you from this Galus. This is connected to above.
2.
Malbim (14, 16): This was salvation above nature, unlike Ge'ulah Bavel, which was via nature.
2)
What is "uv'Mayim Azim Nesivah"?
1.
Radak #1: The matter is repeated in different words.
2.
Radak #2: This refers to splitting the Yarden.
3.
Malbim: Hashem made individual paths in the sea. Chazal said that there was a separate lane for each Shevet (Pesikta Zutresa Beshalach 14).