Can a single piloted ship, like an X wing, fire both it's Proton Torpedoes as well as it's Medium Laser cannons in the same turn, as one action? Or for another example, the Y Wing. It has an Ion Turret, lasers, and proton torpedoes. Can those all be fired with one use of the 'fire weapons' ship action?

In general no. Firing a single system is an Action and typically you are only allowed one per turn. Now a Pilot spec with Master Pilot can convert an Action to a Maneuver so they could fire 2 weapon syetems. A character like that in a Y wing with a gunner could fire all three weapon systems in one salvo.

Thanks! That's exactly what I was hoping.

NP, enjoy.

What the astromech turned pirate said (I recognized you by the red bandana). Also, a GM might allow an astromech (especially a pirate one) to fire the proton torpedoes on that X-wing while the PC pilot fires the lasers?

But no, not as ONE "fire weapons" action.

I'm pretty sure the Master Pilot Talent only lets you do Pilot Only actions as maneuvers. Firing weapons is not one of those.

I don't read it that way. I think the description is written in the way it is to differentiate the use of the Talent so that it is only used in space ships and not with speeders, as they probably knew they were going to have a separate Talent for Master Driver when that spec was introduced.

I'm pretty sure the Master Pilot Talent only lets you do Pilot Only actions as maneuvers. Firing weapons is not one of those.