The “Songs Not Yet Played” is a smart playlist set with songs played zero times (obviously). I haven’t played around with Yaeka’s iPod in a while, but I’m pretty sure all those playlists transfer over to the iPod. Also, the rating question is one Yaeka and I had back in Tacoma. I’m pretty sure we found that the ratings did transfer back to iTunes from the iPod, but further testing needs to be done to be sure.
I just conducted an experiment myself and it appears that yes when you rate a song on your ipod that rating transfers back to itunes. Thats good to know. Now when I am playing my “quality tunes” playlist and something comes up i decide is crap and is unworthy of the 4 star rating I can demote it just with my iPod.