Uwe, when you create form fields in InDesign you have to export it as interactive PDF. Interactive PDFs are always RGB, even the black is RGB.
Form fields are always in RGB, no matter what color space the underlaying PDF has.
Of course, those fields can be flattened. But I doubt that a manager who has no experience in printing software knows how to handle files with RGB sources to become clean CMYK and 100% K text files. I doubt also that she is using or knowing about additional costly tools. I think it would increase the complexity from the given situation.
It would be cheaper to buy InCopy, insert these names and let a professional in her company do the PDFing job.
I think form fields are not supporting specific OTF features, like ligatures, numbers, etc. There is a limitation in form fields.