1. If the player is not too close why not have small objects like beer cans hidden in the bushes with destoy waypoints on them? Take away the plane's other weapons so they can only use the one you want, or just make them select it.
2. Don't know the details, but if you fake it like the music is speech, it will be local to the speaker. It's not much to do with an .sqs, it will all be in the description.ext which is the file that manages sounds. Tutes in the Ed Depot.