Well you already have Linux on your TV. Unfortunately it's android which is capitalist crap. They'll no doubt make it extremely difficult to remove their malware. Even if you could overwrite, you would still be using the shitty computer inside your TV.
Like other people have said, I think the best solution is using an external machine. I use an older laptop running Kodi for my TV. It's pretty awesome. Just make sure your machine has the specs for your needs. It shouldn't be hard to find something more powerful than the TV.
No.
The system is literally genociding people, destroying the planet, etc. It's a major mistake to take their "ethics" seriously. It's just another grift. Enjoy the natural freedom of information while you still can.