Tools like gnome-system-tools or accountservice allow to add the user to the nopasswdlogin group. You might adopt that, to avoid the sudo breakage with empty passwords.
A description of the method: https://wiki.archlinux.org/index.php/GDM#Passwordless_login -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
