I wonder if uploading Roku, on another TV, via my mobile phone(with my account) affects my personal TV viewing?
All apps added to an account download/install to all devices on the account. (You cant install an app on just one device on your account - they auto install to all devices on the account).
In other words, if you installed TRC (The Roku Channel) on that device (assuming it wasnt installed previously on any device on your account), then the TRC app would then install to every device on your account.
As far as "affect my personal viewing" goes - the TRC app will now be installed on all of your devices - the TRC app's "continue watching" list will be the same for every device on your account.
Thank you. So, it would probably be best to have this TV set up on a separate account? This might allow for truly independent viewing?
If you want different apps/subscriptions available on different devices, then yes.
Keep in mind that any of your Roku Pay-based subscriptions from the first account wont be able to be used on the second account (you'd have to subscribe again - more $$) - this is also a(nother) good reason not to use Roku Pay to subscribe to apps/services (and instead subscribe directly to the service provider).