I just searched and found on-line. That thing looks like a drill press. I bet it doesn't have much issue with a 4-ball batch. Mine sort of...well, it doesn't handle it. I'm impressed. Maybe I'll ask for a bigger one next year instead of more guitar gear.
Have you tried the dough calculators on the forum's site front page? You can determine dough-ball size by weight to fit the dimension and thickness factor of the pie you want to make. http://www.pizzamaking.com/dough-tools.html
I don't know about that big of a bubble. I have no idea if this is the proper thing to do or not, but I give mine a big whack when it's stretched out if I have any problem areas that I think might produce a bubble like that. I let one counter-rise too long yesterday and had to do just that. Just be careful not to smash the edge is all. Perhaps another member can chime in with better technique?
Tined, meaning the fork thing while it's stretched out? I've never done it. There are tools for it for pizza, called "Docking" (or "Docker" for the actual tool.) I don't mind a bit of un-evenness.
I don't know the first thing about milling flour. I bet it's been done successfully on this site for pizza. I'd do a search.
My biggest struggles have been un-learning what little bread I "knew" and learning pizza dough. Two different beasts. My first couple dozen had various issues ranging from too hard to stretch, way too chewy and way too bready. Lots of over-mixing using KABF. Some under-hydrated, some too bready. I'm at a really good point right now using a combination of Fazzaro and glutenboy (members here) formulations and methods.
Your oven can produce a fine pie. For me, it was getting dough formulation right. Well, close. Once I was in the ball park, I no longer had any bad feelings for rainy days and having to cook pizza inside. A warm up period helps for me, too. I accidently did an hour one time and discovered that folks around here were right about that issue, too. It makes a little difference on the crunch. Maybe sauce and cheese cook too, but that part was fine only going about 15 minutes after it reached temps. 450F, too. Not saying that's optimal, but a decent pie can be done.