I use Clipious, an Android client for Invidious, on my phone. I selfhost my own Indivious instance so this is perfect in that my phone never connects to YouTube directly, and I can save all my subscriptions in one place without a YouTube account.
On my Android TV I use Smart Tube Next. If I really need to cast, I also have YouTube ReVanced on my phone for just that, but I barely use it.
As soon as Clipious gets a proper Android TV interface, I’ll be set, as both devices can just connect to Invidious and let it do all the work.
You shouldn’t be charged for unauthorized requests to your buckets. Currently if you know any person’s bucket name, which is easily discoverable if you know what you’re doing, that means you can maliciously rack up their bill just to hurt them financially by spamming it with anonymous requests.