I run an all laser python (ish) and picked the Pulse Disruptor laser from Felicia Winters as it has strikes directly against a module provide a chance to make that specific module malfunction. This effect is similar to Scramble Spectrum except it doesn't select a random module and instead if the chance is a succcess, malfunctions the module the weapon directly struck. The Pulse Disruptor weapons effect is also on a separate cool down from Scramble Spectrum so you can more frequently malfunction a target.
I then engineer that Pulse Disruptor with emissive, doubling up on effects on that single hardpoint.
Laser is better, especially in a turret as a fire and forget weapon
mc is better if you want to add some hull damage in the mix, but the ammo needs and projectile speed makes any advantage rather moot
As Northpin said above, a turret is extremely useful, especially when considering no ammo usage. Turrets however do require a bit of understanding to use effectively. Regardless if you use a fixed, gimbal or turreted variant; choosing whether to use a laser or a multi-cannon is going to be dependent on the rest of your weapons loadout. You will want to pick whatever compliments the rest of the loadout best.
For turrets, the "easiest" use case for them is to ensure the right HUD ship panel has turret mode to "target only" and your turret is in the fire group you want it used in. A turret will only stop firing if the fire group is changed to something the turret is not present in at all or if you drop target lock and re-acquire. Turrets in Fire At Will will only shoot at targets who are already hostile and can not be manually triggered to fire - you have to use another weapons system first to aggress non-hostile enemies with them.