No worries with the questions! Ask away! If I don't know something, I'll try it out to see if I can get the answer.
Yes it does. It uses the cellular service from the phone in order to work and allow Alexa to do her thing.
No. It streams music directly from the VIVA from your choice of Amazon Music, Pandora, Spotify, iHeart Radio, SiriusXM, or TuneIn. But, it does route all audio through your car stereo.
Unfortunately not, but you have full voice control of the VIVA just like the Echo and Genie home devices. You can say things like: "Alexa, play classic rock on Pandora." "Alexa, play kids songs." "Alexa, mute." "Alexa, volume 10." "Alexa, next song." "Alexa, shuffle" "Alexa, play." "Alexa, stop." So it bypasses your stereo controls for its own, built-in controls.
When I was setting up the VIVA it connected to my phone via bluetooth. After it was connected, I had to then select my car's bluetooth connection from my phone setup menu. From there it looked like it then connected audio to my car and the syphoned cellular data from my phone all via bluetooth. The audio quality is great! It's crisp and clear.
Let me know if that helps answer your questions.