Convoluted datum help

[[Ma...]]

Okay, so Im in unknown territory here,first time I've had to program datum structures like this. Primarily C and Z are what im worried about. 
unsure on my process for developing datum alignments for this part. Datum C is a symmetry plane, for evaluation settings do you check Normal vector? What does normal vector change? Datum C uses datum Z but datum Z uses C? how would I implement this into my program? For finding Z would a Geometry best fit alignment that consists of AD And the two planes that make up C with or without Best fit checked? Thats what id would assume would be right for finding Z  
As for C just a regular alignment that uses ABZ? 

Thanks! 
partly cloudy and 80F in Colorado today.

[[Ma...]]

I am not sure how in ASME, but i would not constrain vector - in case of rotated shape against one cylinder C it will force vector.

Datum C is axis of a cylinder - nothing to do with TP