OK... I'll answer my own question.
Quote from another forum:
"Pure Music cannot play Movies, TV Shows, or Videos, nor can streamed audio tracks be
played (Internet radio or iTunes Shared files). A fall-back way to play streamed or other
such media is to quit Pure Music and use iTunes, and if you wish to later play file based
audio, relaunch Pure Music. Unfortunately, iTunes controls the connection protocol and
therefore has exclusive control of the audio source."
Regarding managing radio on remote and favorites.
To add a radio station: In Itunes go to Advanced>Open Stream and paste the URL there.
Open the station in "Radio" and right click and add to a Playlist... which I labeled Radio.
To access your favorite stations in "Remote" go to "Playlist" and then, in my case anyway, click on Radio.