Finding down beats in a song

The only way you can ever do something like this is to have something happening on the downbeat that is significantly louder than the rest of the audio on the track. Then you can use the analysis function to put markers where the volume increases. If this is the case with your track, then you need the Diagnostics panel:

As for moving the markers with the file - well I think you should be able to, but you have to make sure that you've put a check in the 'Save markers and other metadata' box when you save the file, which you must do after scanning it, or they definitely won't be included.