Ok, bear in mind that when you use stream, you have to have frames there for the sound to play. If you're at 30 FPS then you need 30 frames to be there just for 1 second of audio...

JPG - you can convert it to a graphic or leave it as it is. If you don't intend to re-use it then leave it as it is.

As for your animation question... it depends what the components are doing. You can do 'shape tweens' with broken apart text and in that scenario the text cannot be a symbol. But if you want the broken apart text to animate AND fade in, then you need the text animation inside a movieclip and then you need to fade in the movieclip as it plays the broken apart text doing it's animation.

It would probably help you to decide on which frame the music stops. If you insert a load of blank frames then you should be able to play from the beginning and see how the music progresses over your timeline.