A) Yes.
Something similar to the following whould work. This will work if the button is on the root timeline and you want the root timeline to play.
on(release) {
play();
}
B) Yes.
You can set up an interval that will call a function that will execute a command to play the movie after a set period of time has elapsed. Like so,
//set up the function to be called. Again note that this is all in the root timeline. Put the following all in the 1st frame.
function playNow() {
_root.play();
clearInterval(myInterval);
}
myInterval = setInterval(playNow, 8000);
stop();