Might be useful to split "Christian -- associated with a denomination" into Catholic/Orthodox and Protestant, at least. It seems to me the responses capture several flavors of ambiguous spirituality but almost no differences in Christian religious practice. Actually, it might be useful to recast the responses to mimic, say, the Pew categories.
Also, since I'm making up work someone else should do, it might be interesting to add a temporal question. Cofty, for example, seems to have gone JW - Evangelical -- Athiest. Something like, "Was there a time between being a JW and your curent belief when you would have answered differently? If so, how?"
Everybody always wants to tweak your survey. I know, it's irritating. Sorry.
Catholic.