sorry i cannot help with the majority of your queries.
i worked for a guy who had a heated motorcourt (USA) of fanned cobblestones. after a couple of years, he traveled and came home with the realization his fans were too
great in breadth.
evidently, in Italy the fans are at the great point radius only as far as the mason can reach remaining stationary at the center.
think of Miguelangelo's Vitruvian diagram.
so the boss came home, ripped out the existing, and had it laid to his satisfaction.