It explains to us two key reasons why this series is re-occurring. However I'm not going to mention it since they're spoilers, but playing the game will answer those questions though. A little hint is that it deals with the Skyward Sword and it deals with the Imprisoned. Aside from that, anyone can learn the rest in the game. It's not too hard to find out (or Zelda Wiki if you're really that desperate). Also, Fi was ok. She was no Midna (my favorite), but that's a good thing anyway. Nothing wrong doing her own thing, thought a little weird calling Link "Master." Was a little creepy at first, but she was useful so I can't complain too much.
But yes, it's a good Zelda game. I'm not sure the top of the series, but it's pretty up there for me.