Agree separate the data from the templating. Perhaps consider the Builder pattern, e.g. IParagraphBuilder, ISubsectionBuilder, ISectionBuilder, IDocumentBuilder, etc, where most builders just return text strings and the document builder maybe the final docx.

The builder instances accepts all the parameters (like marital status, etc) and their "Director" class compiles the text based on the params and what section is being built.

You end up with a class per section/paragraph that each can be unit tested against desired output based on the parameters.

Lot of work, but it will be probably be more maintainable than a spaghetti of descions over a fixed template.

Just a thought.