Thank you FMT, that was an excellent tutorial. I like my pizza crust to be crunchy all over, especially on the bottom. What are the key factors in obtaining crust with crunchy bottoms?
For the hand-tossed or rolled out types that sit directly on the stone or cooking floor, its a function of time, temperature, and hydration. If you want it crisp like a cracker, you need basically all of the moisture cooked out of the crust. If you want NY you still want some moisture left but not nearly as much as Neapolitan. For the pan pizza styles, oil or a cooking spray on the pan kind of fries the bottom of the crust to a certain extent. You may not be cooking as much moisture out but there is a fat involved, which changes the equation. As to your specific question, starting with a lower hydration would be my first step.
As just an observation with no data personally to back it up, I've gotten more crisp from doughs that sit in the fridge for at least a day or two. I'm not sure what the science is there, but I have noticed that over time. Not to say you can't get a crisp crust from a dough cooked on the same day, but there is something about that fermentation time that plays into it.
If you can't get it as crisp as you would like, you would need to play with the hydration, time, and temp. There are a variety of other factors including the balance of temps above and below the pizza. Obviously the goal is to get the crust exactly as you like at the same time the toppings are at the perfect stage of doneness. You could nerd out all day on how to accomplish that, but trial and error is probably the easiest when it is all said and done.
Brand, temp, moisture, and fat content of everything including the sauce, cheese, and toppings all play into how your crust will ultimately turn out. You could have the most perfect crust ever mixed, but if topped the wrong way it can be a disaster. Take a crust that is usually crispy that would be stretched thin. Put too much sauce on, pile on a bunch of raw vegetables, and then top with a cheese that starts to get oily at high temperatures. You will end up with soup instead of pizza. I tried a new cheese out recently that is fairly well respected in the pizza world. Grande 50/50 mix of Mozz and Provolone. I used it twice, and both times the pizza ended up with pools of water in the center. I haven't really done the research to figure out why yet, but I assume I probably cooked it too hot and it fatted out on me. Based on the fact that pizzerias all over the country use this cheese, there has to be something on my end that is causing it to do that. Cooked at 450 in a conveyer oven may melt that cheese wonderfully on a different kind of pizza. It will not be going on mine again until I figure out what is happening.
You may have gotten more crisp on your longer fermented dough because you may have started to have more moisture leak out of the dough from the additional fermentation time. On a pizza stone or steel, that moisture, usually on the outer sides of the crust will sear off quickly and provide crisp, versus a less fermented dough which will hold more of that moisture in the dough when heated at the contact point.
Thin crust has a couple different categories.
1. Roman style. The picture of what you show looks similar to a roman style that shows bubbling when cooked.
2. Plain old thin. Flat, no bubbles, properly portioned toppings.
3. Tavern Style -This can even include pie-like crusts like Home Run Inn pizzas where crust has more oil in the crust versus the overly topped Milwaukee, Minnesotan, or Midwest style where the pizza is overly topped and generally cut in squares. The crust is more of a means to carry the toppings in most of these cases than something appreciated.
Regarding your cheese watering, depending on whether your cheese was shredded, crumbled/balled, diced, or sliced, each of those factors can affect it's melting characteristics. Keeping your cheese very cold (or some add it frozen) to prevent the watering from happening. It's breaking down from cooking too long which is releasing that moisture.