I have a smartlist that I use regularly that gives me a random list of songs that I haven't heard in awhile. I have it added as a favorite in Navigation and both Navigation and Quick Play added to my top toolbar.
If I want to add this smartlist to Playing Now, the fastest way actually is to click Navigation, click my smartlist name, right-click the smartlist name, click Play, and then click Playing Now so I can see everything playing. That's 5 clicks.
Now you can say there's only 2 clicks if I use Quick Play, but the smartlist is nested within Playlists under other playlist groups so by the time I eventually find it, the Navigation way is faster. Sure, I could move it under Playlists but that removes the organization.
Here are some possible solutions:
1. Add a Favorites for Quick Play like there is for Navigation.
2. Add a most recently used list for Quick Play like there is for the right-click commands.
3. Be able to place a Playlist/Smartlist on the toolbar and right-click on that for the normal right-click commands for a Playlist/Smartlist since Play and Add to Playing Now are there.
4. Make right-click under a Navigation favorite work. For example if a playlist was put there, right-click would provide the playlist menu.