Unless the info is out of date (which is likely) kern.log syslog or messeges.

Have you checked the logs in /var/logs?

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.

I would double check that the cpu isn’t too hot for the cooler. I know the i9’s would likely throttle with a single tower cooler but I am unsure of the i7’s. Everything else seems fine.

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.