I like to include screen shots in my posts so here are some screens of the advanced customization options for now playing that I am working on. When choosing the displayed tags, you will now be presented with custom options along with all the presets. Each custom line will let you choose an icon and custom text to display.
So if you wanted to have one line show Track Number. Artist (Rating), you would enter in:
%tn%. %ar% (%ra%)
It looks a bit complicated but I imagine the type of user who wants this level of customization will have no issue with it.