Mint is good, unless it’s very new hardware in which case the base (so things like drivers) can be a little dated.
Look up Ventoy. It’s a tool where you can put multiple ISOs onto one USB drive and boot into any of them. You can use that to try out a few distros. Maybe Mint, Fedora, PopOS, Ubuntu.
It’s in the early stages, but yeah you can do it in KDE Plasma if you’re prepared to jump through a couple of hoops (basically doing the same thing the Deck does)
Linux won’t have proper HDR support until mid-late next year.
Yup. People always latch on to the “Sony (it was actually on Philips, who ran the disc factory that Sony had a stake in, but that’s just nitpicking) installed a rootkit on PCs in the 90s via CDs” and say about how awful that is, and they’re right, then they throw that out the Window and install more advanced rootkits filled with god knows what telemetry when they install games.