Herman, because there isn't a way to bulk delete, it's easier to move an image to a new gallery/category than it is to delete it and re-upload to a new category. Sorry we don't have a way to bulk delete. It's something that really should be built into the software but from what I can tell doesn't seem to be.
Herman, I can easily delete all your photos from the gallery at once (the nuclear option) if you want that. That will remove those photos from the threads where they are currently shown, so it's not an ideal option, but if you want to start clean, it is the easiest way. Just let me know.