You are right, I shouldn't necessarily say "audience," as if he's in command, just that he's clearly capable of being wrapped up into a performance in the manner of an artist. It's something that is supposed to be one of those essentially "good" things, a socially experienced moment of ecstasy, to use your word. By weaving that group experience (something often associated with the essence of being human) with the specific violent character of settler society, your interpretation expands upon mine, so good one there (it has been over a decade since I read it).