Does my radio need to work?
Your radio does not need to operate however since the ON/OFF switch is reused, the switch will need to function. The tuning knob will still be present but is only for cosmetics.
Will the original knobs be used?
Yes
Will the face light up at night?
Yes
Can I listen to FM radio?
Streaming has no direct association with AM or FM radio however some traditional radio stations stream the same content through an exclusive app. You can search the app store for their station ID (e.g. 98FM).
Is this also a speakerphone?
Because this is essentially a Bluetooth amp it does not employ a microphone for voice calls. It will automatically pause the music however when a call is in progress.