1)
How will it be eradicated from being a nation?
1.
Malbim: A nation that fights and falls in war, coming generations remember that it was a nation. However, since [Mo'av] fell like women, they will say that it was not a nation at all.
2)
What is the meaning of "Ki Al Hashem Higdil"?
1.
Refer to 48:26:2:1-2 and the note there.