So the build took around 5 hours.
Mostly because I had no light, cable management was a fucking pain in the ass, and my hands are too fucking big for ITX.
Also my ATX PSU cable was too short so I had to compromise and unscrew my PSU from the case to give some length.
Now to install Arch (using Anarchy).
I'm not using Fedora anymore.
My old PC is now going to be acting as a server.
Time to in-place convert it from Fedora Workstation to Fedora Server (just removing all that graphical and audio stuff, who needs that?).
God damn it.
I HIGHLY regret buying into the ITX small form-factor meme.