I might be buggin but I think Jaquen set up a little test for Arya. I don't think he really intended for her to kill the actress. I think he knew the content of the play which would cloud her judgement and make her act without thinking. I'm thinking he might be testing the other girl, because she's far too emotionally invested in Arya failing. And they aren't supposed to be emotional.
Fred.
Yeah its not adding up. If the Waif is apart of the Faceless Men and she's supposed to be no one why is she so damn jealous of Arya...like you said she emotional and I thought that's against their code.
Also, I find Sam and Gilly more boring by miles for all these seasons...with exception of when he's with the Nights Watch and Killed A WW.
His family may have the coldest castle by the way and his father played his role nice.