That is correct, it aggregates different providers, and also provides integrations with speakers. In my case, I use Music Assistant to listen to my Navidrome music collection over my home speakers that use Chromecast.

This thread might be useful: https://community.home-assistant.io/t/music-assistant-not-showing-players-solved/825283

Are you referring to genre tags? If so, they’re adding that feature in version 2.8.

There is also a Don’t Stop The Music feature, however that relies on functionality from the underlying provider.

The Don’t Stop The Music (DSTM) option can be enabled if a provider is available which supports dynamic tracks (i.e. Apple, Deezer, Spotify, Subsonic, Tidal and YTM). When DSTM is on, radio mode will be automatically enabled when the last track of the queue is reached and if any dynamic tracks can be resolved from one of the providers. The added tracks will be based on the played items in the queue.