Press z.A fairly realistic example of this that comes to mind is Halo's UNSC Archer pod. They are fired in any direction, from a number of separate launch points, and can be aimed at anything they so choose. Yet, as of now, you'd have to point the ship at a target in order to fire them.
We need (First up) a decent free-cam mode, then the ability to lock weapons off-axis (Cannons should definitely be able to fire in a cone, instead of a straight line, allowing for semi-aimed broadside weapons). Especially missiles, which should be able to acquire as a target anything that the scanners can detect...which means no limits on aiming.
Wanda fire weapons? Place camera blocks everywhere. It's what they're for.
All the effects, and a certain % of the primary weapon(configz) . That way you could still need the big barrel, but not all of the blocks. Unless you make a very specialized weapon(which is hard to do with turrets because you can't set priorities), you usually have a decent chunk more than a third of your weapon blocks will be primary. As a starting point maybe 50% of your primary has to be in the barrel. If there aren't enough linked modules in the barrel, then the weapon will only recognize the modules in the base that would make the percentage(I.e. 50 primary in base, 50 in barrel. 10 primary modules get destroyed off the barrel, so the fraction of primary in the barrel is now 4/9, not 1/2. The weapon noticed this and ignores primary modules in the base until the percentage is back at or more than(it rounds up in case of odd values) the config amount. If base modules are now destroyed then the weapon will redo the calculation.I like alterintel's idea. However: Make it so that effects and secondaries can be placed in the base. That way, it acts like a real weapon (Effects are in the ammo, sheer firepower comes from size/barrel length) and is not too overpowered.