Imho, torpedoes and missiles should have been designed like one-time-use-then-discard secondary cannons and secondary turrets, respectively: Torpedoes fired only in-arc, requiring a target-lock, but not requring you to spend it. Missiles fired in and out of arc, always requring you to spend a target-lock.
Torpedoes and missiles should (ofcourse) have lower cost than their secondary cannon and turrets counterparts, but not so cheap all ships will run with them (the price range today seems fine), but then offer another advantage: Torpedoes could all add a crit to the result, and missiles let you modify an attack dice to any result.
