If your oven can go upto 570 that would be an ideal temperature. Pan put directly on the stone/ base of the oven should help the crumb structure be more open.
Typically just sauce is applied & pizza is baked. Removed after 75% completion, topped with cheese & put back in the oven. Most likely has to do with excessive moisture all at once making the crust soggy / excessive browning of the cheese (on white pizzas this is not the case though).
Also if baking directly on the stone at higher temperatures poke a few holes into the pizza so that it does not balloon in the oven. This info is relevant to high hydration doughs pizza al taglio which some of the really good Roman Pizzerias do. I would eat your pie all day erry day
How you close your dough with higher hydration which will eventually lead to a smoother opening process: