Wow, this seems like using a sledge hammer to drive in a thumbtack.
If all you want to do is access files on a local computer, on the same network, any manner of operating system tools will allow that, even for sharable machines that are not in the Homegroup. Just go to the Network section of Windows Explorer, and everything shared should be shown there. If you want to see the screens of networked computers, simple VNC connections would allow that.
TV is useful mainly for accessing computers that are NOT on a local network, or are behind firewalls.
The answer is that yes, TV is a safe way to do it because, of course, TV comes with it's own ID and password. But why? When the internet is down or slow, you'll be satisfied with not being able to reach the computer in the next room?