Not a solution for me. Ran into similar problem. I was too lazy to search online. What i end up doing was I created folders in Mac or Windows. I tossed and sorted my photos in Explorer or Finder. Once they are done, I went into iTunes and select the root folder to sync. Once in iPad, it will create all the folders, matching what I have in Mac/Windows.
Regarding the event sorting, I believe (could be wrong) it sorts by photo timestamp. I believe it just bunch them all together since they are within the similar timeframe. So if you edit a photo, it sometime toss the photo into another event with the similar timestamp. I think that's how it works. 😕
