Why did each man need to take his staff?
Seforno: He took it home to check that it really was his staff 1 and that it had not been switched with the staff of Aharon.
Seforno: Because each prince had placedd an identifying sign on his staff before handing it to Moshe.
Why is "Matosam" written without a 'Vav'?
Ba'al ha'Turim: To teach us that the staffs were as dry as when they were placed.