Howdy, UGAFan!
You didn't say in the OP whether you bought it from the dealer or from a third party, only that "the price was right." Could it be that the price was a reflection on the unit's design? From posts made by others here who are far more knowledgeable than I am, it sounds like there are some serious design flaws. You say that the firebox is too small according to the the calculator, that stack on the opposite end from the firebox looks awfully suspicious to me (gotta be piping out lot of heat, but you could cap it or maybe it has another function?), . . .
We feel your pain, bro. I hope someone here can come up with the answers that will allow you to get you money's worth out of the smoker. Your story will surely help others who might be considering this manufacturer.