A:AnswerYou can download the Facebook app on this TV to watch videos and download the Amazon Fire TV app on your smartphone to control the TV over Wi-Fi.
For Screen Mirroring you can use the Apple - Lightning Digital A/V Adapter -
Model: MD826ZM/A
A:AnswerYes but the TV speakers will shut off I have used this for headphones and there is no way to have them both on so if just want the the out put it will work fine.
A:AnswerThere is only an on/off button right below the "INSIGNIA" name at the bottom center of the TV. I believe it will also serve as an input select button once the TV is on.