So the new Miyako has " This character can only be played by the disguised keyword", so just to clarify..

1. You can't hard cast her and pay 3 fate?

2. You can't use abilities like From the Shadows or Appealing to the Fortunes to cheat her in? If she does gets cheated in, her Reaction can still trigger?

1 - Yes.

2 - No. You can still "put her into play" by methods like Ambush, Appealing to the Fortunes, and From the Shadows. "Played" is different that "put into play". As such, if she is put into play, she cannot trigger her Reaction, as that is a Reaction to her being played, not entering play. Both being put into play and being played count as entering play.