rjm,
Thanks, this is very helpful. You not only answered the question that I asked, but you helped me realize the question I should have asked instead.
My comments will be terse because it sounds like you know what you are doing.
Having been a software engineer for almost 30 years, if I don't know what I am doing by now, I never will.
The key thing you said that helped me understand what I was really looking for was this:
Note: This assumes that you want wife to use your library and and that wife never tags music. It also assumes wife does not want to maintain play counts, etc.
This is true. In fact, not only does she never tag music, rate individual tracks, create playlists, etc., but for the most part, neither do I. What this note made me realize is that I really don't care about syncing the information that is kept in the MC17 database. All I care about is making sure the physical files on her laptop match the physical files on the unRAID server, and I don't need to (and probably shouldn't) use MC17 itself to do that. I just need to find (or write) a small utility that runs when her laptop is online on the home network and watches the server directories for changes. Once the files are in sync, MC17's auto-import will watch those directories and add any new files to its database.
I'll look at SFFS but I will probably end up writing my own to get exactly the behaviour that I want.
Thanks again.