Hi Roland,
I think, that geonetwork has a possibility to generate one metadata entry for each feature of a wfs featuretype. You have to define a xslt script to convert the gml into a iso19139 metadata record. You want a possibility to generate an entry for each featuretype of a wfs. I don't think, that geonetwork handles this at the moment. Maybe some of the developers knows more and maybe there are some other people who needs this function. A similar use case is already available for wms layers - here you are able to build up metadata records for each layer - based on their title, abstract, and keyword elements or their corresponding metadataUrl elements.
Best regards
Armin