Thanks for the tips guys. What a difference some advice and a few mods (spacers under stone, stone raised 1/2 inch, chauflector) makes.
I had all sorts of trouble with the dough (reballed just before bake... didn't want to open), the sauce (not a good brand, blended too much) and cheese (home-made mozz that I messed up the temperatures with)... aargh!
Those problems aside, I persisted, and this is easily the best pie I've pulled off to date. The Blackstone may be everything I'd hoped after all.