A:AnswerMake sure you labtop is set to project signal out of your video card. It's plug and play for the tv but you have the tell your pc to turn on the hdmi port.
A:Answermake sure you setup for HD. I set up an antenna to High Definition channels, check the difference between streaming and antenna . what up stream might not be high difinition.
A:AnswerMy Roku stays connected to my wireless connection. Did you look through the settings to make sure there isnt a specific setting which is disconnecting the Roku? Also, assuming it is a wireless connection how is the signal strength? you may need a booster- Good luck
J