1)
Why does the Torah insert the words "al Son'echa ha'Kamim alech"?
1.
Oznayim la'Torah: Hashem only take-up arms against the enemies of Yisrael who actually rise up against us - otherwise, based on the well-known principle that 'Eisav (incorporating all Nochrim) hates Ya'akov' He would have to take-up arms against the whole world..
2)
What is the significance of the seven paths along which the enemy will flee?