A:AnswerLooking at the unit from the front, the cord comes out on the right side. About halfway between the center line of the set and the right edge of the screen. It is about halfway up the back of the set.
A:AnswerI never tried it, but the TV does have 3 USB inputs. I suggest taking your drive to the store and seeing if they can make it work on their floor model.
A:AnswerNo built in WiFi.
I do not know if a ROKU stick will work on it. It does have 3 USB inputs. The ROKU I added to mine was powered with a receiver that plugs into one of the USB's. My ROKU is glitchy, but mostly needs to be power cycled from time to time. I don't know if a stick would have that problem.
A:AnswerThis is not a Smart TV, it does not connect to a Wi-Fi network.
You can hook up an external streaming device into one of the HDMI inputs on the TV.