A:AnswerIt is not a Roku tv, so Roku is not pre-loaded into the tv. If you have a Roku stick, then yes, it would work. It would just plug into 1 of the HDMI ports.
A:AnswerYes, you can download the Sling APP. Look at YouTube tv because you get more channels including local w/o having to extend packages. Also get free DVR, no fee.
A:AnswerYou may need to get a converter that transfers digital sound to analog for the older receiver. There is an audio output you can do this. I too have older speakers and an older receiver. The sound works fine on my very old receiver, it’s just not digital, but my ears don’t notice the difference. My receiver is over 20 years old.
A:AnswerPress the home button (looks like a house) on the remote and scroll until you see the LG apps screen and push enter. I don't remember seeing a Pandora app, but I may have overlooked it.