In the Settings option of Nelio Content you can delete a social profile from Nelio Content. Doing so, nobody can schedule new social messages nor any scheduled message will be published on that profile. However, Nelio Content will still have access to that network, since you can have other websites that do have configured that profile and thus need to post messages on it.
To completely delete Nelio Content permissions, do it on Buffer. Access your Buffer Preferences and in the menu select the App & Extras tab.
Buffer will show you the list of apps that have access to your account.
Select Revoke Access to Nelio Content and, after confirmation, Nelio Content will not have access to Buffer. Of course, you’ll always be able to grant Nelio Content access to Buffer again and then publish to Google+ or get Instagram reminders.