A:AnswerYes. I have a 65" UHD Curve TV that I plugged a 2TB disk drive into a USB port. The drive is recognized and I can play all of my movies.
I just bought the 82" 6F QLED. I am expecting it to do the same.
A:AnswerI can’t help you with why it would flash or strobe but I use Roku to facilitate all of those services and many more channels. It’s much easier than the smart TV Apps. I have not had any problems with the picture this way. I don’t have cable and use Hulu Live streaming service.
A:AnswerOLED is the better technology for TV's if the intent is watching movies. They can do real black and have better color. OLED's are not as bright, and they do get burn in so they might not be the best options for games, etc. OLED's are much more expensive, the 77" OLED's are selling for more than double what this 82" QLED is selling for.