Thank you for the kind words!
You can use the DLNA interface of plugin of the Server to make all players DLNA/UPnP compatible. Then you can use apps like BubbleUPnP or AllConnect to stream from your phone. You can also check for the casting symbol, some apps natively support dlna streaming. AllConnect also offers AirPlay.
Regarding your sidequestion, I’m not exactly sure what you mean. There’s the AirPlay bridge plugin which can use to turn AirPlay speakers into Squeezeplayers.