They're shooting in directions I don't want them to, though...
The actual problem emerged with the FS2-style beam cannons... if I assign only a single beam cannon turret to the weapon slot, it'll fire in all directions, even right through the hull. Only solution was to alter the tacticstypes.ini to include a CannonMaxFireAng restricting the fire angle of the beam cannon. This works well, but only for flak-style turret placement in Lightwave.
This approach worked well with the previous ships, but the ship I'm currently working on has a huge beam turret, which needs to be animated in order to look good. So I'm kinda stuck here, if I don't want to alter the original FS2 weapon layout of the ship.