

do any of you hate how self-hosting services like photo- or document-management systems, or even a simple rss tool, forces you to sort your stuff out, and put your decades old files in order?!
What is this “sort” thing you speak of? I don’t sort anything, I have NextCloud syncing my entire photos, videos and documents folders and they are just as messy as ever. Granted, I do go through my photos and videos once a year and dump them in a folder named for the year they were taken. Occasionally, I’ll go hog wild and try to sort some of a year’s photos/videos into folders named after events. Though, that hasn’t happened in a number of years. I setup NextCloud so I could have everything synced to my own server and just forget, not have to deal with labeling my data.
As for bookmarks. I already keep those in folders; but, I don’t sync those. I use my desktop far more than I use my phone for web browsing. And the types of things I use my phone for (mostly recipes), I just keep bookmarked there.
A couple thoughts. Assuming your motherboard is capable of SATA hot-swap and has it enabled (look in your BIOS), you should be able to umount the game drive, and swap it without shutting down. Assuming the game drives are partitioned using GPT, you should be able to add individual entries in /etc/fstab using the partition UUIDs and control mounting and umounting to specific mount points for different drives. Personally, I would add the noauto option to those entries, so that mounting is done manually and can be controlled easily.
OS drive swapping may be simpler, depending on your BIOS. With the system powered off, swap the drives and assuming the BIOS picks up the new boot partition cleanly, you’re off to the races. The only issue would be if the BIOS just doesn’t want to recognize one of the drives’ boot partitions. I had this issue with my Arch install and my MSI motherboard. The motherboard won’t recognize the default install location and I had to move the boot files around to work in a fallback mode. Annoying, but solvable.
Finally, as others have said, this could all be a matter of over-complicating things. Why not just stuff all the drives in the case and always have everything? You can configure the primary drive’s boot loader to let you pick between which OS to boot. And you can have any and all data drives mounted at the same time. Unless you are struggling with physical space or power requirements, it saves on having to muck about with swapping stuff.