Parashat Bemidbar – Opening Questions

What need was there for a census in the beginning of the second year of the nation's travels, if they had just taken one a few months beforehand? How is it that the tallies of the two censuses were identical?
When and why was the tribe of Levi chosen to replace the firstborns? What did they do to merit the position? What did the firstborns do to lose their status?
The events of the opening chapters of Sefer Bemidbar appear to be recorded out of chronological order. When did each of the laws and stories actually occur, and why might the Torah have preferred to recount them in this manner?

Parashat Bemidbar/Questions