If the user deletes some lines from the config.ini.php file, there should be a warning message asking the user to add the lines that were deleted (helping the user giving the default values for example).
Or shall we use some default values contained in a "default" configuration file?
what is current behaviour when config file value can't be read? should simply link to the default config file content, online.
I don't have a use case where this is a real problem.. marked as invalid until a user reports a bug.