1)
Why does the Torah write "B'nei Zevulun" and not 'u'Venei Zevulun', like it does by the other third-listed tribes.
1.
Ba'al ha'Turim: Based on the pact that they made with Yisachar - to provide them with Parnasah, it was in order not to make him look secondary to Yisachar - to teach us that those who support Torah are on a par with the recipients who actually study it. 1
1
This is difficult however, bearing in mind that, in the desert, everybody was fed by the manna, and nobody worked - in which case the pact between Yisachar and Zevulun would only have taken effect once they entered Eretz Yisrael. See also Oznayim la'Torah, who elaborates.