Is there any possibility in the near or distant future that Noteworthy will organise the possibility of inserting turns and mordents in the PLAYING mode, I know that there are numerous possibilites using the WRITING mode.
Often it is necessary to create two staves, one to actually play the part but is never displayed--the other displays (prints out) the part but is muted. Look at your sample file Moonlite for an example of this in Page Setup. NWC understands the notes da-DA-da-DA-da-DA-da-DA but not tr vvvvv, but that is what you would print.
The attached is an example of a turn. The font boxmark2 available on scriptorium (http://nwc-scriptorium.org/helpful.html#Fonts) shows the turn while the NWCSTDA font (already on your system, comes with NWC) displays the sharp.
HTH