What is the connection between this Pasuk and the previous Pesukim?
Rashi: When Hashem scattered the Dor Haflagah, He did not destroy them, because Hashem's portion - His people, Ya'akov - was contained among them and was destined to come out from them. 1
Ramban (on Pasuk 7, citing the Ibn Ezra): This relates the uniqueness of Yisrael, "Ha la'Shem Tigm'lu Zos!?" - 'How could you do this to Hashem who raised you to such a high level, which He did not do to any other nation!?' "Am Naval ve'Lo Chacham" - 'In your foolishness, you fell from that level!'
Rosh (in Pasuk 8): It explains why Hashem started [arranging] the inheritance of Yisrael - since He took them for his portion.
What are the connotations of "Ki Cheilek Hashem Amo"?
Refer to 32:9:1:1 & 3.
Targum Yonasan: Refer to 32:8:3:1*. It means that Yisrael fell to Hashem's lot.
Why does the Torah mention specifically Ya'akov?
Rashi #1: Because he was the third of the Avos and who possessed a triple merit - that of his grandfather (Avraham), that of his father (Yitzchak) and his own - like a rope of three strands. 1
Rashi #2: All Ya'akov's sons are Hashem's portion
Avraham did not Daven to have a son from Sarah (refer to Bereishis 16:5:1:1), and when Hashem said that he will have a son from Sarah, he requested that Yishmael should be a Tzadik ('I would prefer this to having a second son'
What are the implications of "Ya'akov Chevel Nachalaso"?
Rashi: Refer to 32:9:2:1.
Seforno: It implies that Ya'akov and his sons (and sons' sons) are servants of Hashem - but if a Chasid is to be found among the other nations, his status is not passed down to his descendants.
Targum Yonasan: When Yisrael fell to Hashem's portion, 1 the angel Micha'el announced "Ki Cheilek Hashem Amo!" and the Angel Gavriel opened his mouth in praise and declared "Ya'akov Chevel Nachalaso!"
Hadar Zekenim and Rosh (in Pasuk 8): "Chevel" is synonymous with 'portion' - The Pasuk therefore means that Yisrael is Hashem's portion.