And if it is no longer controlling your tv the volume keys won't work either. The only way to get it to not control the tv anymore is to go through tv programming again but lie to it. After you tell it you hear the music playing, keep clicking NO even if the music stops, only click YES when it doesn't stop.
settings> remote & devices> remote> remote in use> program tv> follow prompts
All of your channels and any subscriptions you've taken out through Roku reside in your Roku account. As long as your Roku is linked to your Roku account, it (and any other Rokus linked to this same account) will have access to your channels and subscriptions. The power button on the remote only controls the tv and has no affect on your Roku(s) or Roku account.
The only ways to UNlink your Roku from your account are: