Others have answered your dual-booting question pretty well. However, along the lines of “minimal” Windows, it’s not generally recommended to fuck with the system as that can break things. There are scripts that can strip a lot of the problems, though. I can’t remember any off the top of my head.

As for not requiring an account, I have old ISOs of Win11 and Win10 where the unplugging my ethernet cable trick gets me around signing into a Microsoft account. Not sure if it works on the ISO you get from Microsoft now, however. And if you have built-in WiFi, I think there’s a way to disable it in the command prompt before you install.

Edit: Win10 is going to hit EOL in the near future. I am going to use it until then. It’s got a lot fewer concerns (for me) than Win11, unless Microsoft keeps filtering Win11 shit into it.

Yep, dual disks with the Windows installation done first is how I did/do it. GRUB/systemd-boot worked just fine from then on, and I am not on Windows 11, so I didn’t get hit with that fuck-up Microsoft did just a few days ago.

Yeah, VMs are a good route since the OP didn’t mention gaming.