I had a migration from Ubuntu 18.04 to Debian 10 two weeks ago. Both systems ran/run fine with 1.0.0beta3 and TS3.3.0
Admittedly I have no idea why the script is messing up, and frankly I don't even want to.
My tip for anyone is the following: You can use a script, if you understand what it's doing, to make your life easier. If you use a script, and got no idea what it's basically doing, then you're eventually always depending on others help.
The fear of non-GUI is real, but unneeded. It just takes a while to realize the actions.
Learn what files are important to backup. Back them up. Afterwards nothing can happen to you... of course care for the backup.
So now you are free to do a fresh install and try yourself out. If you fail, you can still you the installer. But don't skip it, because of laziness.
If you want to cook, there's prolly no way getting around heat.
Same goes for Sinusbot and command line.