Timed events at specific time?

What happens when you comment out main() completely?

Also, looking at your "log" printout, it appears to be working, except for the actual sound interface.

Have you tried writing a simple sketch that only plays a file? Not all the other stuff?

Also I see this:

  out = new AudioOutputI2S(0, 0); // Output to builtInDAC

Who says, the output to builtinDAC? Can you reference the documentation on that?

This kind of obscure code is a good reason to develop a simple test sketch first.