Check what exactly? Run wireshark 24/7 and inspect every network packet for the malicious bits?
Firewall for http traffic while blocking everything else can easily check for weird connections. If you use your TV for browsing, better buy a PC.
"Easily", you would use this word for such activity, really? And what's the criteria for "weirdness"? Are you inspecting payload for every packet of legit apps for weirdness? How do you know they are not exploited? And for how low do you propose doing this "easy check", 24/7 forever? I'm utterly baffled by people suggesting things like that with a straight face.
If you are not sure what to look for, an LLM might help you set everything up including alarms when something atypical happens between the TV and its content sources.
ITT: we learn how firewalls work
Rude. You could try explaining instead
I am unfamiliar with LG TV software but I would imagine that you can reinstall it after rooting and use custom software that you trust.
You’d need proper hardware support and I’m not sure a vanilla Linux kernel can do that, but WebOS has its own Linux kernel and LG MUST publish the source (we all love the GPL, don’t we?)