The multi-canons don't have great range. If it's more than 1.2KM out, I wouldn't really bother wasting ammo. If you find that your target is more than 1.5KM out a lot of the time, consider changing flight tactics and learn to throttle down/turn sooner so that you get right in behind him if he passes you in jousting, so you can keep behind him and at close range more often.
Remember, all kinetic weapons except the rail gun require time for the projectile to travel from weapon to target. This means that you'll have a solid stream of fire at the target that doesn't just disappear when you let up off the trigger. Keep this in mind when you're dog fighting along side system authority ships.
Also, turn off your S.O.S.
Left-side panel, functions screen, shut off the option that calls for help if you get attacked. That will reduce the number of police vessels that arrive, lowering your chance of accidentally shooting one.
4 burst lasers is a LOT of heat and a LOT of weapon capacitor. That's a pretty bad setup for longer fights with anything bigger than a Viper/Cobra (and probably with those ships, too)
Here's my Epic Viper (and add to that a point defense system, two class 2 multi's, two class 1 pulse lasers, and a kill warrant scanner):