Fighter torpedoes (not the MR) have always been kind of an outside choice, particularly the Sunslayer.
Right now, they're a weaker choice than ever, sacrificing a slot that could be used for a CD or MR for something that's too weak against anything bigger than a snub, and too slow compared to missiles is not exactly attractive.
I suggest giving the Starkiller similar treatment as fighter missiles: much higher speed and tracking ability (though still inferior to cannonballs), as well as higher damage and lower ammo capacity.
The Sunslayer could indeed perhaps be made into a mini nova, too slow to hit snubs except in "mine ram style", but with something like 50k damage. Enough to noticeably dent transports and gunboats.
That would also reward team piracy, with one CD-less pirate dealing heavy damage to a transport while his teammate prevents it from fleeing.