"Followed the guide to a T"
"Never upgraded"
"More Fuses burnt"
NO. Not possible. Upgrading firmware is what burns fuses to begin with. Nothing else. At 1 point your firmware WAS UPGRADED. Your fuses burnt BECAUSE it was upgraded and you turned off AutoRCM.
TegraRcmGUI has ZERO to do with any of this. It doesn't touch or run off of your switch. All it does is send the payload.
At any rate, worrying about fuses is completely useless if you ever planned on using legit games and services. RCMloader is a fantastic and cheap device so you can use CWF and such on the go when you need to, and keep your sysnand 100% legit and ban-free (assuming you don't use CFW/Homebrew with it to alter save files and/or cheat).