The beams use surprisingly much lesser capacitor energy than pulses or plasma. You can fire very long and for a really long shot, mossfoot already mentioned, fire a heatsink. Than you can hold the trigger for about 10 seconds.
The heat generation is also much lesser than with the plasmas. My first thought was, the Dev's have confused plasma and beam behavior.
I think i don't need chaff. When i got shot in the fighter than only from railgun and PA (yes....) so far. I think one or two times also from frag canons but gimbaled weapons never got me in the iFighter. It was always a fixed weapon that has knocked me out
(npc's are cheaters.....)