4. That last scene... was Elizabeth twisting the knife on purpose? She's an expert in handling people, telling Philip that he's a bad Russian is not really going to help.

I think she's getting personally angry at Philip and does want to hurt him a little--maybe she's thinking of her father a bit. But also, while Elizabeth is good at handling many people, one of the great things about her and Philip's relationship is how unable they are to "handle" each other. Here I think she was doing what she usually does in these kinds of situations, explaining herself and hoping for understanding/agreement.