If you're looking for a wide range of games tested, NizVicious. FreddysGamingBenchmark focuses on the steam deck. EtaPrime usually test all his builds in linux at some point but it's mostly the same games as he's a hardware channel (newer titles get added though).
TrueNas gives you a lot of options and it isn't too obtuse. I recommend Scale over Core. Avoid it if you only have the one drive as the os won't share its drive with the rest of the system. Also, while you can use it with only one "storage" drive, it will complain because it uses ZFS and expects you to set up redundency across at least two drives. Might be a hassle for your form factor, but worth a look.
Watch a truenas setup for it snd compare the permissions maybe? I got it working on my truenas server but it takes a long time to spin up so it seemed borked but was just slow to start. Not directly comparable, I know, but any port in a storm.
Use the comments on protondb. They often list tweeks and troubleshooting steps that have been taken. Check steam community posts for specific games. You can also make your own post if nobody else has had your issue. General searches will usually get you where you need to go. I use kagi but generally anything not google works.
There are places in the city that are worse than others for performance but I've only ever noticed stutters and the like while driving. Do you use power utils? I don't have an overclock but I make sure the governor is set to performance. Could just be luck on my end though.
I've been playing cyberpunk a lot on both my pc and deck. I thought that it would be a way worse experience going from desktop to handheld, however, it really is a decent experience. I've had the same luck with other games as well. Cyberpunk specifically runs avg 40/50 after I installed CryoUtilities and changed the vram buffer (for those who are curious).
You need Windows installed first, set up your partitions, then install Linux. You could backup your data and then restore it. That's the easiest way if you choose not to use a windows vm.
If it is cloud hosted then there is always a possibility. Programs like keypass run locally and are only in jeopardy once your system is compromised. The issue with keypass is implementing it for multiple users is probably a chore (never looked into it).
If you're looking for a wide range of games tested, NizVicious. FreddysGamingBenchmark focuses on the steam deck. EtaPrime usually test all his builds in linux at some point but it's mostly the same games as he's a hardware channel (newer titles get added though).