A:AnswerI had no problem getting my Roku to work. Just connect the HDMI to one of the ports and it should be detected. If not you may need a new ROKU.
Closed Captioning is in the accessibility section.
A:AnswerYes. I have attach a Samsung and a couple of insignia sound bars. When setting my up, I saw the list of virtually every sound bar. It will just depend on the connections ( HDMI, Bluetooth, Optical Audio, or 3.5mm audio/RCA cables.