Hi
Glad to hear you got everything working.
Just a few things.
One: did you create a bootable repair disk using Todo backup, it's under the Tools tab.
I prefer to make them on a DVD, and use the Linux version, but you can do it on a flash drive too or using Windows PE.
I ask because you said that you used ImgBurn to create it and that's not necessary.
Just use the utility in the Tools folder to make a repair disk.
This is different than writing a ISO file to a disk.
The process installs the the EaseUS Todo software to the disk and makes it bootable so that it will run the program from the disk and restore the hard drive without running it from your hard drive.
This works even if you computer is unbootable.
As for changing your user name, I don't think there's a problem with that especially the new non Microsoft account.
But I believe you need to do it from your Microsoft account.
Read through this...
Change Account username in Windows 10.
And if you ever need to find the registration code for any of your software there is a free program that will tell you everything about your computer including all your software license numbers.
It's called Belarc Advisor.
It's actually kind of scary how much it can see in you computer (even things like the serial numbers on your motherboard, drives and ram sticks) but it's safe to use, I've used it for years as have other people here.
I've had to use it several times to find the registration number on software that I needed to reinstall.
Belarc Advisor - Free Personal PC Audit, for software, hardware and security configuration information on your computer. Software license management, IT asset management, cyber security audits, and more. Make sure you make that repair disk!!!
Mike