Best Way to Set Up Mass Firing of Projectiles

I want dozens of turrets on a moving ship all firing a specific projectile object at a rate of several per second, over the course of about a dozen seconds. I want the projectiles to combine the velocity of the ship when they were fired with their own forward velocity (so if the ship was moving sideways then, the projectile should move part sideways, and part in the direction it was fired). I then want all those projectiles to disappear when they hit a specific object, ideally spawning a specific hit effect object at that position and time (or making it visible and active then, or whatever).

What’s the best way to do this, with scripting or otherwise, without going crazy? Thanks!