30 Seconds is a LOOOONG time in a combat situation. If it takes you 30 seconds to move 6 yards/meters, then fire yours weapon and then run into an attack you are moving really slowly. I guess the movement phase could be 5 seconds, shooting phase 5-10 seconds and assault 10 seconds.
It's not like you empty a clip in the shooting phase, you pop off a few rounds. Burning people for 10 seconds with a flamer is a loooong time, the short range of the template suggests short bursts of flame rather than a prolonged firing.
Mag. It's called a mag.