I think you hit the nail on the head. Yes, bread + topping is by definition not pizza. Pizza is made with raw pizza dough and toppings, not with already-baked bread.

Of course if the pizza dough is wrapped around the toppings/fillings and pinched around the edge in a half moon shape, now it is a calzone, not a pizza.

Or is it an empanada? ;-)

And thank you for that list! I have never had sabich or lahmacun, so you have given me some new things to try.