1)
Why does the Torah fail to list any of Gad's grandchildren and of Asher (in Pasuk 17) only the sons of Beri'ah?
1.
Targum Yonasan: Because all the grandchildren of Gad and all those of Beri'ah were born in Egypt. 1
1
Although Targum Yonasan does say this specifically, it is clear from his explanation in Pasuk 2 (Refer to 46:6:2:1) and 17 that this is what he holds. And by the same token, we can assume that if the Torah (verses 23,24) does not list any of Bilhah's grandchildren, it is because they were all born in Egypt.
