I am just about to set up my new Linux machine, which will be used to convert analog video and audio to digital video and audio. Is there any reason why I shouldn’t run the system off of a live USB stick (say, a good quality one from Sandisk), that is, without installing Linux on the hard drive and not setting up a boot partition, a system partition, and all that?


You do have an asus prime case. The smallest is the 201.
Here is the manual showing where to mount three 3.5” drives:
https://www.manualslib.com/manual/2851351/Asus-Prime-Ap201.html?page=19#manual
You bolt them to the bottom.