When I ask Alexa to play WUSF, I get "Tune in live is not available. If I manually open the app, I can play it that way, but through Alexa
This is the Amazon Developer Forum, where developers come for help with the development of their skills. Features available (or not) on Alexa do not fall under this category. If you are having issues with an Alexa feature, I would suggest getting in touch with customer service here who should be able to assist with your matter further.
Alternatively, you can post your questions on the Echo & Alexa customer forum: https://www.amazonforum.com/forums/devices/echo-alexa