You don't give us your credentials and viewpoint concerning the scholarship. When did the Princeton prof publish his work? Without enormous effort, why should we believe your stance that a particular scholar is excellent. Some excellent scholars are seen as mediocre or off point with the passage of time. It is very true in Art History. Most of the masterpiece painters were dismissed in their lifetimes and other painters elevated. When we see the art through today's sensibilities, one can't possibly imagine what contemporaries saw.
The bottom line for me is to not repeat the WT errors. I know enough from the relatively small bit I've studied that such a discussion would take up many heavy books and a slew of scholarly articles to even pose the questions raised. Frankly, I care about 1st century practice. Christianity was really many Christianities. It was my understanding that the Coptics and the Egyptian Jews were isolated from the rest of the world. The isolation needs to be addressed.
I'm not saying you are wrong. As someone who was so impressed with the Witness quoting secular sources, I demand a much higher burden of proof. Also, reference is made to one strand of Coptic translation. Do the competing strands agree?