Hello,

If you are attacking with a ship that does not have a forward arc, but instead uses a turret to attack (e.g., Jumpmaster 5000), can you attach a cannon to it so that it gains a forward arc only for that cannon attack?

So if I have a Jumpmaster 5000 with an Ion Cannon attached, if its turret is pointed to its Rear Arc, can I still attack out of its Forward Arc with my Ion Cannon? Essentially I am asking, do ships gain the firing arc of secondary weapons that are attached to that ship?

Yes

Yes.

Important quibble: they can use that arc to fire the cannon (or torpedo, or missile) only. They do not gain that firing arc for the purposes of things which check whether something is in or out of a given arc at other times than when firing the relevant special weapon.