You don't need to update the Firmware. If you want to update, it's pretty easy. Even as a non-programmer.
What is the problem with the installer of Debian? I installed several distributions. Almost all worked without a problem. Debain, too.
https://wiki.raptorcs.com/wiki/Operating_System_Compatibility_ListAbout glamour etc.: You only have to create a file and C&P a few chars. That's it.
In the meantime, it would be good to collect some Linux experience before buying a BB.
Linux is different from Windows or Mac. You cannot install Linux and expect a MacOS. Linux will remain Linux.
If you are looking for support, IRC is very helpful. There are mostly developers there, but everyone is very helpful.
But what is really basic is the will to educate yourself and the ability to use Google search properly.
If this will is not brought along, then it will be very difficult. Because as I said, Linux will never become MacOS.
I had MacOS before my BB and the beginning was really hard.
But maybe you're right and some things are changed in two years. I have no objection