1)
What is the meaning of "Kol Hovish"?
1.
Rashi: They all shamed themselves to acquire masters for naught.
2)
Why does it say "Al Am"?
1.
Rashi: It was Bishvil (for the sake of) the Am; it will not help.
2.
Radak: This is like El Am, like "va'Tispalel Al Hashem" (Shmuel I, 1:10) is like El Hashem, "va'Yelech Elkanah ha'Ramasah Al Beiso" (ibid., 2:11) and similar verses.
3.
Malbim: [They accepted all the shame on themselves] Ba'avur Am (in order to get Egypt's help, and it did not help)!
3)
Why does it add "v'Lo Leho'il"?
1.
Malbim: [Also] no other benefit will come from this.
4)
What is "l'Cherpah"?
1.
Rashi: It is [to be subjected to] blasphemy.