The basic Falcon is an absolutely incredible ship for everything except getting quick kills. Its combination of high speed (faster than all but 1 Destroyer), full cruiser range, cruiser flux systems, and cruiser PPT would be completely busted if it weren't for its low overall firepower. Something like 2 heavy needlers, 1 Ion beam, lr pd lasers, and ITU is very good at locking down enemy ships while staying alive.
I agree with the OP that the Falcon P is overly strong in its pure missile configuration because it has the OP to max its capacitance rather than vents and not suffer at all in firepower. It can have a very, very tough shield on a fast platform - perfect for point blank sabot barrages.
I like the idea of removing the built in expanded racks better than penalizing the mount type however - its still an OP tax, but a less harsh one.