Playing from a Macbook Pro straight up, nothing fancy. My library of music is on an external USB drive in the original folders where iTunes put them. I have write permission to the folder the songs are in. Some songs are greater then never, but that could be from last time iTunes played them.
I don't have a Mac but whenever I hear
My library of music is ... in the original folders where iTunes put them. , can't help to think that that would mean they are all over the place. Make sure your autoimport configuration paths include the places where I tunes put 'em. Might be a good time to re-organize the hard drive and then run auto-import manually or better use the rename tool. Backup your data base files (library files) first just in case!
You can force the number of plays if you want .. but number of plays and things will not be ported over manually from itunes. SUggestion: once you get this sorted, either get rid of itunes completely from the mac or disable any autosync options in its options --- don't let itunes mess with your files ... don't let it "consolidate" files or handle the image files if you want to keep it on your machine.