You don't really need any vintage computer skills beyond loading floppy disks. They'll load at power up or if RESET is pressed. You just need to make sure you have the correct disks in the system and this is where it can get tricky as some games have many disks that are labeled as Disk 1, Disk 2, Data 1, Data 2 etc etc and that can be confusing. Basically you'll need Data 1 and Disk 1 to start the game and then you'll eventually need to swap out for Disk 2 but leaving Data 1 in and eventually when you get to a new town or area you'll need to change the data disk. Lagoon was a bitch. It took me a while to learn how to boot up Ys 3 and this is how I found all this out.
You forgot about keys you have to hold during start up to enable midi, high memory mode, etc. (which you mentioned in the video). I don't know how anyone does it without having the original manuals and being able to read them, frankly.
Try getting into PC-9801 gaming. Then you oftentimes have to deal with required installs, boot disks you have to make manually using elements of your own system software, and tweaks you have to make to the config.sys and autoexec.bat. And, since it was such a long-lived line of computer architecture, you have to take into account the system requirements and whether your machine meets them, or is so much newer than the game that the programmers never expected it to be run on such a fast processor, or on such a large hard drive. It all just leads to stuff not running correctly, and oftentimes having to come up with clever workarounds on your own. It's basically like relearning the ins and outs of the American"IBM Compatibles" of the early 90's, except with different rules, and in Japanese. For me, trying to get a game to run can sometimes be part of the fun. I wouldn't recommend getting into PC-9801 if that's not your idea of "fun".
Other Japanese retro PC's are relatively straight forward, and similar to what you described above. X68k, MSX, PC-8801, X1, FM7. FM Towns maybe qualifies as medium difficulty if you delve into games that don't just simply boot from CD... Okay. I'll shut up now.
