When I move a category, I make a backup between each interaction.
I've had to restore the website more than 12 times because the moves don't finish, some images are moved while others are still in the old folder like imageproxy.
For gallery it's more problematic, your script modifies the CHMOD of the folders making them inaccessible requiring you to contact the host so that he can modify the rights and finally realize that the root folder of gallery has been corrupted, resulting in a partial loss of documents and files requiring you to restore the website.