Try lower temp for pizza, I cook most mine at 475-500. parchment paper burns at 550. I wait 4-5 minutes to pull paper and sometimes I don't pull, don 't notice much difference. My guess stone was to hot and maybe to big not allowing enough air above the stone, maybe stone was closer to 600-650 crust burned very fast and toppings not done. Next time do same but shoot for 475 temp.
I would definitely add some air space or another layer of fire brick under the egg. That paver stone gets mighty hot. Next 400 degree cook place your fingers on the bottom of the stone under the egg and see how hot it is. Realize that as wood goes thru many heat/cool cycles it lowers it's burning point, thats how tables start on fire. When I first posted a pic of my new egg and table on the other forum several old timers were quick to point out that I needed an air space. Now I have a paver, layer of fire brick and the original BGE feet.
I don't like lump that smokes excessively after start up, I have had some that after 1 hour you still would not want to put food on the grate, I think this has to do with under-charcoaled wood. GFS was my go to until recently when I started finding lots of "wood" not charcoal in the bags along with insulation. You'd pour some in and spend 5 minutes going thru it looking for under-charred pieces and other matter. Most of my cooks are in the 400 range followed by low and slo's. Really one hour before you dare put food on the grate.
I also have a pet peeve about paying more per LB for charcoal than the food I cook, that just seems wrong.