I'll be happy to help you create the report you need, usermyles.
You can run the Transaction List by Tag Group report and set the Group by to None. Then, click on the small gear icon on the report section, click Show more and place a checkmark in the Ungrouped tags checkbox. This will show you the list of tagged and untagged transactions.
To filter the list of untagged transactions, you can export the report to Excel and remove the tagged ones.
If you have other questions, you can always go back to this thread.