I had to delete all of the subVIs in order to run it. After that, I could stop the VI. You said "ALL the sTOP buttons refuse to function". There is only one button that will stop the VI. It's the abort button. Start the program and just press the abort. Does it stop now? If it doesn't, then its possible that one of the subVIs is stuck in a loop. since you posted the subVIs without diagrams, no one can look at them.
Your top loop's initialize is never run. The wire coming from the Create Queue and Insert Queue Element is connect to the output of the create queue instead of the output of the insert queue element. This means that the User Abort Setup indicator is never getting set. Its value ANDed with anything will always be false, never stopping the lower loop.
Using the Abort button to stop your VI is like using a tree to stop your car. It works, but there may be consequences.
