Private Playlist sharing & changing public/private

[tomstephens89]

I am pleased we now have private playlist functionality, to be honest its a basic feature that's been missing for some time, however bit of a lack of news/docs on how it works, where are the playlist files stored for example?

Specifically, I have two questions as follows:

1. Can I share a private playlist with specific users on my server?

2. Can I change a private playlist to public and vice versa? 

Thanks!