1)
Why does the Torah write here "be'Seifer ha'Torah ha'Zeh" and above in Ki Sao, 28:61, "be'Seifer ha'Torah ha'Zos"?
1.
Rashi: Refer to Devarim 28:61:1:1.
2)
What are the connotations of "Vehivdilo Hashem le'Ra'ah mi'Kol Shivtei Yisrael"?
1.
Ramban (in Pasuk 19): After alluding to an individual and a family in Pasuk 19, 1 "Vehivdilo Hashem le'Ra'ah" refers to a tribe and "mi'Kol Shivtei Yisrael", to the rest of the nation
2.
Rosh and Hadar Zekenim: He thought to separate from Yisrael to do as his heart desires, but Hashem will separate him to destroy him.