Did you livestream and run into trouble or are you just curious? If you, personally, had an issue please give a summery of what happened.
It's legal on paper but in the real world it's cop baiting. Do you really want to give an officer a reason to escalate a traffic stop to your detriment? An ounce of prevention is worth a pound of cure.
The officer could be concerned for his own safety if the traffic stop is live-streamed, yes.
Yup. As surprising as it may be to some people, states actually want all drivers to concentrate on their driving instead of watching movies, texting, or posting to Facebook and Twitter when behind the wheel.Also, it's illegal to have anything that can display videos operating in the front seats (with small exceptions).