I personally would love a way to sort multiple items at once in my inventory. It takes forever doing it one by one, I wish I could like click a bunch of check marks and just donate them all or move 'em to my vault or my store?

Under Commerce at the top bar hover over "Your Shops" and then click on the (qs) next to your shop name. That's the quick stock page.

That exists, you need to have at least one shop/gallery and then you just go to quickstock or click the (qs) on the dropdown

Oh my gosh I feel so silly, thank you two for informing me!

No problem. Even after over 4 years I am still discovering new things. :)