But a normative theory of agent behavior will need a normative theory of identify if identity is to be a central element.

Doesn't causal decision theory also require a theory of identify, which you have to use in order to provide CDT with a set of possible choices? For example, in a Prisoner's Dilemma game, you could identify with both players, and make your choice set the four pairs {<C,C>,<C,D>,<D,D>,<D,C>} instead of {C,D}, but presumably you don't. If you're puzzled about whether you should view yourself as controlling the actions of all physical objects under TDT/UDT, why aren't you puzzled about this same question under CDT?