Maintain Access to Free Channels?

Hope someone can clarify on this question -- these days, what exactly is needed as a Channels DVR subscriber/user to maintain access to the various "free" add-on channels that are provided?

Is is enough to just be a paying Channels DVR user?

Do you have to have some TV Everywhere authentication in your DVR sources?

Does a Locast subscription alone suffice?

How about a regular "free" Sling TV subscription alone?

Thanks much!