I will give you my two cents worth.
Until you have a chance to go to Naples and see things for yourself, I would do as both David (BrickStoneOven) and I have done, and several other members have also done, and that is to read all of Marco's posts, or at least those that are directed to the Neapolitan style. The objective is to absorb as much as you can, like a sponge, without trying to come to any particular conclusions or form specific opinions as you read his posts. You should read his posts as a neutral observer trying to learn. As you go through the posts, you should keep in mind that Marco is just one person, with his own opinions, many of which can be quite rigid and inflexible. And, as has been noted, a lot of what Marco has written about is related to a commercial pizza operation. But there is a treasure trove of information in Marco's posts. You may struggle to understand some of the passages in Marco's post, both because English is not Marco's native tongue and also because he was intentionally cryptic and vague in many of his posts because he was planning to write a book on Neapolitan pizza and did not want to put so much on the forum that no one would buy his book (he specifically mentioned this concern). I think that that was why he deleted certain posts--because they gave away too much information. Marco will never get a Miss Congeniality award, but I think he was misunderstood and unfairly maligned by some of our members who expected him to reveal every nuance of his knowledge of the Neapolitan style, in most cases without giving back anything in return.
As I look at your original questions, I know that Marco answered a lot of them in his posts. If you read his posts, you will also get a better feel for the politics that is pervasive in the VPN arena. And you will see who uses/used natural leavening systems, preferments, and commercial yeast and the related protocols. Ultimately, what you want to take away from your reading are the things that will mean the most to you in your particular setting, with your particular oven, and your particular personal objectives and aspirations. That is where you will put your personal and unique imprint on your version of the Neapolitan style. And I am sure that you will be applauded for that.