Hello,
I'd like to suggest rclone have a delete everything protection. (I know there is already a max-delete, but it isn't very flexible because it uses a static value as an option, not differentiating if there are many files or very little).
I'll give you an example, I was syncing a Google drive, but the owner suddenly moved it to another account and because the original drive was empty rclone wiped out everything locally.
It could be as simple as if remote root folder doesn't exist or is empty, don't touch local files.
Thanks,
Mike