They could be using a 32GB chip on either side of the board to save space. That would give the new phone up to a 64GB capacity without using 64GB chips. And when prices come down, they can use one 64GB chip for the same effect. Then they can use two 64GB chips for a 128GB iPhone next year.
It looks like both the Gizmodo phone and Vietnam phone had shields over some components (all in the Gizmodo phones case), so that would be hidden.
Not if they plan on fitting in the chips for a cellular radio.
Pay attention.....3 generations of iPhones have all had a SINGLE NAND CHIP. There's no reason to assume or even guess that they may change that. The preponderance of evidence points against it.