I'm treating this as more of a learning experience than anything. I basically posted this because I wanted to know if I was on the right track, which obviously, judging by your response, I'm not.
As for the ATC/VTC thing, my picture doesn't include one part that would be inside the throat chamber (too hard to see it inserted in the model). With the piece installed, it would provide 1182 square centimeters of chamber area. And I designed the chamber so that when the driver is at peak outward excursion there is 1182 cubic centimeters between the driver and the chamber walls. I'm guessing this was an incorrect assumption on how to calculate those numbers. And just curious as to why it would tear itself apart so quickly? The construction materials are also almost identical to the LAB12 driver.
As for the driver, I selected it because of it's similarities to the LAB12 driver. I assumed the Fs wasn't the best. But the Qts is almost the same as the LAB12 driver (0.40 vs 0.38), it's got 3.6T-M more BL than the LAB12, and only 0.8 dB less sensitivity. To me, it looked quite capable in comparison to a driver that I know performs very well in horn loaded situations.
As for the complexity of the enclosure, I designed it with ideal curvature/angles. To build it, I would obviously modify the design to use flat panels instead of so many complex curves.
This isn't meant to be argumentative, just an explanation of where my thinking was coming from.