Well, there's no reason to sing past the end of the combat, so with either of those I was imagining a "pick up where we left off and maybe never finish" scenario. For a more audience-friendly version of the song, I like the Frank Hayes version.

I love the idea of NPC antagonists! I'm not aware of them having that, but I've only played once and skimmed the high-level rules. That would open up some fabulous bardic powers, yes!