1)
Why will they be ashamed?
1.
Radak: They were not able to fulfill their intent, that Yisrael never leave their Reshus.
2.
Malbim: Yevoshu (they will be ashamed by themselves) and Yikalmu (they will be ashamed in front of those to whom they spoke bad about Yisrael).
2)
What is the meaning of "Necherim"?
1.
Radak: This is from the root Charah (to be angry), like "Bnei Imi Nicharu Vi" (Shir ha'Shirim 1:6).
3)
Who are "Anshei Rivecha"?
1.
Malbim: They quarrel with you to your face and disgrace you. Yovedu - they will cease amidst you.