1)
What is the meaning of "v'Nasu Es Kelimasam"?
1.
Rashi: When I will do good to them, and not pay them like their evil, they will bear their shame and be embarrassed to lift their faces. Radak ? it is as if it says v'Nas'u with an Aleph after the Sin. They will bear the shame in their mouths and recall the shame that they had in Galus.
2.
Rashi citing Menachem: This is an expression of Kaparah, like "Ashrei Nesuy Pesha" (Tehilim 32:1).
2)
What does the verse teaches about "v'Es Kol Ma'alam"?
1.
Radak: When they will dwell on their land serenely, they will recall that they suffered shame of the Goyim due to their sins.