i agree with what you've said, in parts. i also believe rosalind is RJ, for several reasons. first rosalind, roses, roses are red. john? male counterpart of jane. patrick jane. as a way of reminding herself of what he did to her. her hair is also red.
when rosalind is talking about 'roy' , the man she loved; the way patrick stops and stares i think shows us he is reminded of something. perhaps a long time ago patrick rejected her, and she is telling her story in the way that it triggers some of his memories, but washes over them because she is talking about 'roy'. she enjoyed playing piano for him, the way his wife and child did (as it was shown in an earlier episode).
the teacup is another clue. and the way the smiley face is drawn on the wall, perhaps for practice? it is not the usual smiley face, but perhaps is the first face RJ/rosalind ever drew.

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