by manydills
The Song cards make the resources on a hero usable for more than one sphere. It does NOT provide an extra resource per turn.Yes, you raise your threat by 3.
You are referring to the FAQ/Errata list maintained by FFG. Go to fantasyflightgames.com, navigate to the page for the LoTR Living Card Game, and click on "Support". You'll find what you're looking for. There are also similar helpful files on BGG.