Did I goof? Reversed mediums...

It is best to keep the brood nest together, intact. If you moved the queen upstairs with the brood she may not cross over the empty super (or one full of honey) to get back to the bottom box. Is the now middle medium bow drawn comb or foundation only? It may not be too late to change it back. Did you move the nurse bees with the brood? If so they will go ahead and care for the brood. I think your biggest concern is the queens location.
Personally I would keep the deep on the bottom. Maybe next spring you can make adjustments to your arrangement. I am not familiar with using 8-frame equipment. However, I do know that a typical brood box in a 10-frame set up is two deeps. You may have to do the math to figure out how many 8-frame boxes of which size equals the same brood nest area. Maybe two deeps and a medium should be dedicated to the brood chamber and supers stacked up from there?
For a robbing situation you need to reduce the entrance to make it a more defensible position and hope for the best. If you are using an entrance feeder that could create an issue. Maybe your local beek did not realize that you had only brood nest area and no honey supers? He would probably not have recommended to break up the brood with an empty super.