Thanks for taking the time to help me troubleshoot my problem @mdooley I'll answer your questions first and then I'll go on my small rant
I installed Unetbootin from the ppa. I start the app by selecting it's icon in the application launcher. A window pops up which asks me to enter my password. I enter my password and press enter and the app starts. I have formatted the usb several times with disks and gparted.
Here's the essence of the problem. Unetbootin is a straightforward app with a simple and user friendly layout. It has no settings whatsoever. Theoretical it should create live usbs with persistence just as flawlessly on my system as it does on yours. Yet, it doesn't. Yes, it's not in the repos, so it hasn't been tested extensively with UM or plain vanilla Ubuntu - but it's so straightforward that this doesn't make a difference. It's a more sophisticated version of the usb creator app. For a new user, it gives UM/Linux that classic windows "plug'n'pray" & "just reinstall it a 5th time and maybe it will work" feel for no reason at all. I'm a huge fan of UM that's why I'm writing this.
I spent enough of my time getting this to work - so I'll go back to what I was doing before. I'll use the LM live usb if I need to restore system snapshots and the UM live usb if I need to nuke & pave. My plan was to repurpose this LM live usb for something else - so now I'll need to go buy another one - thank God they're cheap now