Unfortunately it isn't possible to get ships to fire on one another or on shore targets.  There is an add-on available that allows you to simulate an artillery shell exploding.  There is also a modified cruiser out there that has flashing guns.  Together I've used them to simulate shelling a beach. It works, but requires writing a mission for each use and a little effort to get the hits just right.

wasnt there a way of fooling the sim into thinking the ships were aircraft, thus allowing them to fight each other?