+1 for the request, and I've already added Playing Now as a toolbar button. As discussed, the full solution would be the ability to almost fully customize the menu items and positions.
One oddity of the Playing Now mode that when it is clicked, the Playing Now menu branch always expands to show two options I never would use while Playing Now: Find CD and Artist Info. They mess up the tree, pushing more useful items further down, and it's never user-friendly to add clutter to the UI, especially in playback mode which is most-likely to be used by less technical family members.
Even odder, these appear when I do NOT click on Playing Now. My playback PC is set to automatically switch to Playing Now when clicking on a playlist/smartlist to play it -- and that causes these two menu options to get revealed.
Of course, these options can be useful, but during list playback? They aren't really options of Playing Now, they are just things to do with a track in MC. I'd guess they are used 99% when working on the library, reviewing, tagging, etc. Why force them to display every time Playing Now is selected?
A much more useful Playing Now submenu would have the options that actually affect playback, such as which visualization/track info, which plugin/DSP modes to use, etc. These options are buried in other menus, yet they are what I most need to diddle while Playing Now. (Please, even if these options are added as the Playing Now submenu, don't have it auto-expand.)