I finally got to doing an experimental clean install during which I imported nothing but "Your files and folders."
First thing I found was that my
"less than 200k" was only kinda correct; the import was 245.5
Mb.
I then poked around a bit to see what I could see, and
- the only obviously imported stuff I found was a handful of minuscule invisible files identified as "(from old Mac)," and
- I found that /etc/hosts had not been updated, so my original conundrum remains a conundrum.
So I'm left scratching my head and wondering not only what on Earth I imported, but in what state my new installation would have been had I not imported it?
Edit: If there's a Terminal command I can run that might identify my mysterious files and folders I'll be happy to rerun the experiment.