Right now my profile picture is a plastic duck, there are no photos and no information apart from my name and my throwaway-email adress (which I hope is hidden from the world via settings).
There is also a "privacy page" there where you can check what information they have saved about you and if you forgot to delete something. I would probably have done it this way first if I where to delete my FB-account but for now I need messenger.
If you are running firefox you should also install "facebook container" even if you don't have an account. :)