Jay, I think everyone has gone through a packet yeast phase. I used to spend a lot of time worrying about expiration dates, storage, viability and proofing, and, now that I look back, I probably worried way too much about it. That being said, using jarred yeast, and having relative consistency for what ends up being about 140 pies, makes me giddy. I think you will be far happier using jarred yeast.
I've had high gluten bromated flours go to 5x on me. If you take a bromated flour 60ish hydration dough, one that hasn't been kneaded too much, and leave it at room temp for long enough, as long as you have a few live yeast cells, it will double and triple eventually. It might start to collapse around the 4x mark, but that's not the end of the world.
Dough does deflate quite a bit when forming the skin, but if you handle the dough relatively gently and don't press down/deflate the rim, you can end up with an airy rim going into the oven- a rim that will expand even more with oven spring and become super airy.