I would suggest you take a backup of registry before making any changes. Please confirm that the mentioned key in the logs are related to McAfee. You can do this by navigating to HKEY_CLASSES_ROOT\CLSID and searching for keyword "mcafee" without quotes in Find dialogue box.. If a key is present you can go ahead and Delete it. Post back if you receive any error message at this point.
If you receive any error try renaming the key and delete it. After deleting the keys Re-run MCPR tool and check if the Un-installation is Successful.