After many hours spent working out the kinks, I finally finished a heavy cruiser/battlship with functional secondary weapons. The controls are a bit complex, so ill try and explain them as best I can. Group 1: Activates bow turret, missile launcher and secondary rotation (VTOL). Group 2: Activates aft turret and missile launcher rotation (VTOL). Group 3: Enables port side secondaries. Group 4: Enables starboard side secondaries. Trim will adjust elevation for both turrets and missile launchers. You steer mostly with roll, and I suggest throttling up to turn as the VTOL thrusters do a better job than the rudder and VTOL maneuvering thrusters (used with yaw).
Enjoy!