I thought you had created an auto-playlist that you were playing from? You can't apply any of this directly to the Playing Tracks list. Make your auto-playlist, limit it to something like 500 tracks selected by least often played. Then load that into the playing tracks list using right click > Play Shuffled. Play the list until it's done, then go back to the playlist, which will have updated to account for the new plays, and do the same thing again. You might get more repeats while the numbers even out.
Incidentally, MusicBee will tell you in the status bar how much time the tracks shown in the main panel will take. My 500 track playlist clocks in at 1 day 8 hours. Unless your tracks are very long, if you're playing music 15-16 hour a day, you'll run through 2000 tracks in a week or so.