As far as your music goes ... use iTunes instead!!!
LW will struggle to play consistently if LW is too busy. Playlists are only reference files ... the LW playlist in iTunes is simply a playlist & if you move any of those files then the playlist won't work! Import the songs automatically to iTunes & forget about the LW playlist & you'll be fine. Other than that, have a look the at the
Stickies in this section & look at the iTunes threads & links.