An addition to your list: Use mainstream technology media formats for physical storage. It's trivial to get a USB floppy drive for reading floppies from the ea

An addition to your list: Use mainstream technology media formats for physical storage. It's trivial to get a USB floppy drive for reading floppies from the early 80's, but getting hold of a new drive to read LS-120 disks from the late 90's/early 00's is pretty much impossible. BluRay is probably the best bet for physical media for the next 20 years. I've done some trials with SD cards but they seem less reliable than BluRay.