I have a rather coarse textured rectangular one I bought and didn't like all that well that stays in the oven and gets spilled on etc. I don't cook on it, its just for stabilizing the oven temperature since I don't like it for anything else. I have a round pampered chef one that seemed almost pre-seasoned (which made me wonder with what) that I cook mostly cookies, biscuits etc. on since I'm yeast dough challenged. Choclate chip cookies make a mess of it so I take a soft mushroom cleaner type brush and with some plain water and the brush scrub off the worst of it. When cooking cookies I put the dough on the room temperature stone for the first batch, then after that since its hot I switch to the aluminum pans if making a whole batch (often I freeze the dough in small batches since I'm single and just cook one stone full of 6 cookies at a time). Haven't had a problem with the 'cold' stone going into the oven. Who wants to put dough on a hot stone?

Yes, use a pizza peel. A sprinkling of cornmeal acts like little ball bearings so the pizza will roll right off, onto the stone, if you give a quick snap of your wrist. You need to sprinkle your peel with cornmeal, then make your pizza on it, then transfer to the stone in the oven. If you don't have a peel, you can improvise by using the back of a cookie sheet. You don't want to use parchment when using a stone. The point of using a pizza stone is that the stone is porous, and as such, absorbs some of the moisture from the dough, so the crust becomes crisper. If you use parchment, you might just as well bake your pizza on a cookie sheet--the stone won't have the opportunity to do it's job properly with the barrier between it and the dough.

Cut it flush. Drill it out with a long bit such as those used by electricians when going between walls. They are about 6-8' long so you won't get wet. I think Home Depot has them in the Electrical aisle by the Klein brand tools. Scott

Set up your pipe wrench to grab it. Get a length of iron pipe or steel or a large enough closed end wrench to fit over the end of the wrench. This extends the 'lever' effect of your wrench. It's likely you'll unthread the sleeve from the copper fitting behind the wall. Get a new sleeve along with the new shower head. Or use a vise to separate the two once removed.