while i can’t guarantee great performance without a better idea of your PC specs, if it runs fine on windows for you in all likelihood it should be playable on linux for you too!
i’ve been playing XIV on endeavourOS for probably the past two years without any major issues i can remember. the only minor thing i’ve had it do to me lately under some window managers is not properly take focus sometimes on an alt-tab, making it run a little slow until i try it again or raise the window another way.
edit: as far as Bazzite goes i don’t have personal experience with it but i’ve heard good things. if you’re new to linux as a whole though, i hear that Linux Mint is probably the easiest to get your feet wet with!
First off congrats on your build!! That’s gonna feel great after dealing with a chromebook.
For games you’ve got great choices in there but I’m gonna vote XCOM 2. I’ve had a weird hankering for missing 99% hit rate shots at point blank myself lately.