I moved to GrapheneOS about a month ago, not too long after the announcement. Bought a used Pixel and jumped. TBH moving to Graphene was something I'd considered for a while for privacy reasons but Google gave me that last push.
There are some different ways of doing things but I've really enjoyed the transition overall.
Your understanding of Linux is about 10 years out of date my friend. Linux has made massive strides in ease of install and use in recent years.
If you're not playing games - and the people buying these machines probably aren't - then you'll have as stable and easy an experience with Linux as you would with Windows
But most (all?) Torrent clients let you select which files you want to download so of there was an official unarchived torrent then archivists could seed forever and others could select the ROMs/manuals/etc. that they wanted
Musicbrainz?