Not exactly what you want but if your listenen to your favorites playlist and remember a song you want to listen to just hit the menu button and go through til you find the song and press and hold the menu button and you should get a few options like insert append replace etc.. and that will add it to your current playlist.. as for the hide from parent bit I believe thats where the wendy filters come into play, though ive never had any luck with them cause I wanted to hide entire playlists not specific tracks and my understanding is it cant do that...