1)
Are the numbers mentioned here and in Pesukim 9,16,24,31 & 32 referring to another census?
1.
Ramban: They are all part of Hashem's command to Moshe and Aharon in Pasuk 1, and Hashem is informing them how many each Degel will comprise when they travel. 1
1
Ramban: And the Pasuk is coming to teach us the tremendous miracle that took place here, inasmuch as, bearing in mind that there were over half a million men, during the twenty days between the command (on the first of Iyar) and the actual traveling (on the twentieth), not a single person died. Refer also to 1:1:6:3.