I was hoping to find more information on the pizza pan you are using but it appears that it may have been discontinued. However, from the Amazon.com description, it appears that your pan is made of aluminum, not steel, and it is anodized. I thought that perhaps your pan was a thin, inexpensive one prone to buckling or warping, but that would not appear to be the case (in fact, a reviewer at Amazon said that there was no warping after several uses of the pan).
I don't see anything from your dough formulation or preparation methods to explain the problem you have been experiencing. You would perhaps have to use a pizza stone to rule out the pan as the source of the problem, but that would mean having to get a large stone to handle the 16" pizza size or else make a smaller size pizza if you have a smaller pizza stone.
Out of curiosity, I went to the pizzatools.com website to see if they have a pan that most closely mimics your pan and the closest I could find is a 17" dark, anodized cutter pan, at http://www.pizzatools.com/SearchByCategory.aspx?CategoryCode=052000
. As noted in the description for the cutter pans, they are designed to be used for medium to thick crusts. Your crust, with a thickness factor of about 0.10 (my best calculation), is either a thin crust or on the cusp of a medium thickness crust. However, I have made thin crusted pizzas before using my cutter pan without incident. But, to get a more expert opinion, I called pizzatools and spoke with a customer service rep about your problem. She consulted with one of their engineers who said that it sounded like steam was being trapped under the dough and was causing the air pockets. The engineer suggested using a perforated cutter pan or a perforated disk, either of which would distribute the heat more uniformly across the bottom of the pizza. In either case, the oil could be applied sparingly or an oil spray could be used. The perforated dark, anodized pizzatools.com cutter pans are shown at http://www.pizzatools.com/SearchByCategory.aspx?CategoryCode=051000
. The disks are shown at http://www.pizzatools.com/SearchByCategory.aspx?CategoryCode=056000
I might add that pizzatools is not the only source of dark anodized pans and disks. I think that they are one of the best companies for pizza items (I have several of their products), but American MetalCraft is another solid manufacturer of dark, anodized pizza pans/products. Unlike pizzatools (or its affiliate Lloyd Pans), AM does not sell directly to the public. But their products are sold by most restaurant supply companies, both online and brick and mortar.
I can't say whether the perforated cutter pans or disks are the answer to your problem. I am always reluctant to suggest that someone spend money on something and not have it work. But at least you have additional information to take into consideration.