From my short experience with the Sound class in AS3, I'm not sure if it is the best choice for detailed and accurate sound handling/processing.

It seems that you just want to play a simple mp3 player with a predetermined and randomizable playlist. Depending on the length of your sounds (less than 5 secs) there might be a space interval between clips. I can think off the top of my head some methods to bypass this but overall—and given your specific question—I don't know if I'd recommend you to go ahead because I don't know what other "choices" you have.

Now, take all I say with a pinch of salt. I'm fairly new to AS3 myself and I only talk from my experience. I just figure it's better to have a reply from a newbie than no replies at all; support's what this board is about.

Good luck.