Firefly averaged around 4.7 million total viewers if I recall.  Agents of SHIELD had 12 million viewers for its premiere and had dropped to 7.7 million by this week's episode.  Still significantly more viewers than Firefly ever had.

Yeah, I agree, last week's was good, but not earth-shatteringly great.  This was week's was just as good, if not better.  Different strokes, I guess.

It's actually got very good ratings for its network, and they put together quite a large Emmy campaign for Maslany once it was clear she had critical support.

Thank God.

Yes.  Her second and third CDs are amazing.  She's a fantastic singer and performer.  She came off as pretentious at first because she was an angsty 19 year old when Tidal broke huge.  She's matured since then.