Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
That's strange - but also kind of vague. Do you mean: Some channels won't download to the TV? They do, but display error messages? Something else?
I recently switched from one Roku to another, and all the channels I had downloaded automatically. (Since they were connected to the same Roku account.) The one that I pay through Roku was all set up to go. The ones that I don't pay through Roku needed to be re-logged-in or re-linked. In the case of where I need to re-login in, I had to login with the credentials for that service/account, not the Roku account credentials. Just throwing out some ideas since I don't know where it's hanging up for you.
You can add a Roku device to the new TV or just use it as a Google TV. You will have to add your apps to the new TV but most apps that work on a Roku device are available for the Google TV. Most paid apps like Netflix can be added to both the Roku and Google TV. You may have some apps that work on Roku that are not available on the Google TV but you can cast from your smart phone for most of those apps. I have one app Big Ten Plus that has a Roku app that does not have an app for a Google TV. Google TV also has a few apps that are not available for Roku devices.