A:AnswerYes, your Apple TV will airplay to HomePod. You go into Video and Audio in Setting and select the audio output to be the HomePod. It will also airplay to two set up as a stereo pair. Anything you play on Apple TV works this way (movies, Netflix, etc).
A:AnswerIf you’re asking if you can use 2 HomePods together to give you surround sound, the answer is yes. They will connect together and detect each other in the room so they can direct the sound in the room directly towards to.
A:Answerin the home app, on the ios device you used to set up the homepod, there are options for settings up multiple alarms to ring at certain times. i’m not sure whether or not volume can be controlled for set alarms
A:AnswerThe algorithm Apple uses allows the sound to be distributed accordingly. I'm no audio engineer so my best answer would be to just check this link out.
https://www.apple.com/homepod/