The photos I had edited on Lr Mobile on my iPad are gone. Nowhere to be found. Not on the iPad, not on the computer, not even in the bin. GONE. I was moving some files around in my Lr Classic a couple of weeks ago, and I can't help but to think that I might have moved them or deleted them by mistake. Is there a way around this?
Upgrading from free usage to a paid subscription should definitely not cause this to happen. What you describe would only happen if you uninstalled and reinstalled the app before subscribing and syncing your photos, or if you signed into another account by mistake which doesn't sound like the situation here.
If you had accidentally deleted Lightroom and the images were gone after you re-installed the app, perhaps you have an older iTunes backup of your device that you can restore? If so, try restoring your device back, and then try the same advice above to see if iTunes can help you recover any images.