re: "I have set it up to do so, including authentication with user name and password, but seems to only sometimes sync play counts and only when I tell client to do so manually. Like I played a song, and no matter what I do, it still shows as never played."
Just a followup that I got this working.
This should probably at this point go in different part of forum, but since I mentioned it here I'll note the resolution here—
Next day, same guest machine from same host server, the library would not even launch. I forget error; shoulda written down. Told me to check internet, for one. Internet was fine.
I tried turning off and on Authentication, as I had read on forum, to generate new password and get it working again. Still would not launch.
Then I tried
Advanced » Reset sharing key (makes all shares invalid)
the suggestion of which I'd not come across in my search, and that did the trick. Library launches, and so far syncs.
I think maybe when first accessing the remote library if you don't right then tell it to remember password, you may have trouble. It never asked again, and just would not sync even when restarting etc. However I could not really test that out much, because next day I could not get library to even start, which was only resolved by the sharing key reset.