Bearing in mind that Hashem made the inheritance of the seven nations contingent upon Yisrael keeping Torah and Mitzvos (See 4:1 and 27:3), why does the Torah need to repeat it here, in connection with the Keini, Kenizi and Kadmoni?
Ramban: Based on the fore-knowledge that Yisrael were worthy of inheriting the land of the seven nations, the Torah is speaking here after Hashem had already decided to give it to Yisrael 1 through Moshe and Yehoshua. But to inherit the remaining three nations would require all of Yisrael to love Hashem and to go in His ways. 2
What are the connotaions of "Kol ha'Yamim"?
Ramban: It does not refer to a time period (without a break 1 ) but to attaining such a high level, 2 that Hashem Himself testifies that Yisrael will never come down. 3
See Ramban DH 've'Amar R. Avraham'.
Ramban: With reference to the era of Mashi'ach mentioned later in 30:6 and in Yirmiyah, 32:30 & 40.