I don't know about the nerve pinch, but Wikipedia sates that the Vulcan salute was "based on the hand symbol used by kohanim Jewish priests during the Priestly Blessing in the synagogue." and that "as a child, (Nimoy) peeked during the blessing and witnessed the gesture, although the congregation are supposed to put hands over eyes or turn away at this moment in acknowledgement of the presence of the Almighty."
