I think the main issue here is that not all devices will recognize the 10TB HDD as it is GPT formatted, which is the standard for anything over 2TB. The two solutions I have found are:
1. Using a Windows based mini pc that can traverse video and audio over HDMI, and be mounted to the back of your TV along with a wireless keyboard and mouse such as this to control.
2. Using an Android based set top box paired with the Kodi App to play the files off your your external hard drive.
Alternatively if the laptop has HDMI you should be able to tuck that away in the closet with a long HDMI cable and still use a wireless mouse / keyboard combo to control it remotely. Does the audio / video pass through you surround sound or does the surround sound receive a different type of input such as RCA or Optical? Either way if you are routing the TV’s sound output to the surround sound input then anything you plug into the TV should have it’s sound come out of the surround sound.