tinfoil at the bottom of the oven (to catch crumbs) is ruining my pizzas I put a sheet of tinfoil at the bottom of my oven to catch crumbs because I cook pizzas on the rack all the time.  This is ruining my pizzas though, because when the top is done the dough is still gooey.  Should I raise the pizza higher? Use a different material?  I donno if a pizza stone is an option... I often get papa murphies pizzas which say to cook in the tray and are usually quite large (16"), but am willing to try breaking the rules if someone has some good experience with other methods.
I would probably go ahead and get a pizza stone. Even if you don't want to bake your pizza on it, you can just keep on the floor of your oven (unless you have exposed coils/burners there, in that case, go with the lowest rack).

The pizza stone is easier to clean, and as an added bonus, it'll improve your oven by keeping a more even temperature in there.