How can I get rid of this?
Option A: Use the Remote Player instead (simpler version of player)
Option B: Create a solo session and use Session Player to watch a YT video of your choice.
Option C: Drag another window over the video-box section and watch that instead.
Option D: Pop-out the components you want to view (ex, rainbow gauge and power chart) and close the Session Player. Drag/drop and resize the components where you want them to appear.
Option E: Wait for an update to Session Player due out soon. Not sure what changes it may include but others have requested what you want.