NinJake

Depends what game(s) you're playing and what settings you're trying to push out of it as well.

https://www.microsoft.com/en-us/software-download/windows10 Going there will provide you the latest version of Windows 10. You may need a few updates but nothing compared to starting on an older version of Windows.

Are you able to backup your important data/files and do a clean install with the current 1909 installation media? Would save you a lot of time troubleshooting except for re downloading software. Edit: I see you stated you don't want to reinstall windows. Sorry, but without a bunch of troubleshooting, this is normally the easiest/quickest solution.

I've also got a 2TB WD Black for storage. When it's in use or needs to spin up it's definitely noticeable. Solution? Turn up the tunes!

Path of Exile Pretty cheap: Risk of Rain 2 Terarria CS:GO

Don't sweat it, imagine being Amazon during black friday/cyber monday. Suuuuuper understaffed most likely. These people are bustin' their balls trying to get everything shipped on time. Just due to the time you ordered I wouldn't worry too much. If it says it'll arrive monday, wait until at least tuesday before you call anywhere. I have had shipments on the weekends too, however I'm not in CA. (I actually have a cable coming this Saturday, come to think of it.)

Are you trying 1 USB drive that's not working or multiple? Can you try another computer or a live linux environment to see if they are recognized?

Mind as well remove the screen next!

There is no 50/50, somewhere there is a configuration telling that software to save where it's saving. You just need to find that and change it. If you are telling me you uninstall Project Zomboid once and it saves to your C drive but uninstall / reinstall and it saves to a Z drive without changing anything I'd have a hard time believing you without some sort of proof lol.

The C drive is normally default for download locations. The key is to pay careful attention with software installers for the "save location", which normally you'll have to manually select or go to some sort of "advanced options" to change yourself. Some other things you will come across are: Each web browser (Firefox, Chrome, Edge, etc...) will have their own setting within their software to change default downloads. For Firefox you go to options, (about:preferences) then to the Files and Applications section and Browse to your other drive for mass storage. For things like Steam games and other game browsers such as Epic Games, you'll have to go to each of their preferences/settings and change your default save locations as well.

Never heard of it. Sorry to hear if you were employed there. There's always a better job somewhere, just gotta find it!

Also nothing. Likely going to build a new rig next year however.

What are your computer specs?