Does my SAM Broadcaster Cloud subscription cover music royalty payments?

No! your SAM Broadcaster Cloud subscription package doesn't include any kind of copyright royalties.  When using SAM Broadcaster Cloud, you either agree to play content that you own or that are not subject to copyright royalties (e.g. public domain), otherwise, you need to make sure you obtain all required licenses and pay any applicable royalties or other fees to display/reproduce/perform/post  your content through our technology.