I am with you all on the lack of playlist editing - seriously annoying. I cannot imagine how Microsoft dropped the ball on this. I am happy to say there is a way to edit your playlists though but it isn't intuitive. Here are the basic steps.
- Install Windows Phone app on your desktop
- Connect phone
- Open Windows Explorer window
- Find your phone in the media list under Computer
- Double-click Phone folder
- The Explorer window will not show 'Search Phone' in the Search box in the upper right
- Replace 'Search Phone' with the word 'playlist'
- You should see a hidden folder named Playlist - Open that folder
- All of your playlists should show up as PLA File - Double click the one you want to edit
- The properties box will open.
- To add music, drag files *from your phone* to the playlist window.
- To remove files click the red X. Use the arrows to rearrange music.
- Click Ok and it will update your playlist on the phone
- Write to Microsoft suggestions list and tell them they really need to fix this.
Hope this helps,
-Bill