A:Answer First, to switch between the Roku and the laptop you would best be advised to get an HDMI switcher available from Best Buy or Amazon. The monitor has two HDMI inputs and can switch between the signals, but using the tiny control at the bottom of the monitor is far too cumbersome to constantly use for switching between HDMI signals. Save yourself some navigational headaches by forgetting that tiny control and buy an HDMI switcher. Plug the Roku and the laptop HDMI cables into the switcher, then connect an HDMI cable from the switcher output to the monitor's HDMI Input 1.
I am currently using another LG monitor tethered to a Roku. It works fine and this monitor should yield comparable results. You will need a speaker, as you mentioned, connected from the monitor's AUX output. I'm using a JBL bluetooth speaker that I keep plugged in all the time for my audio output.
