Why do you want to the same tool to do validation and reporting?
Indeed. Because they may be functionally the same, with some tool capable of wearing more than one hat.
For example, if you want "validation" to mean "testing that an XML instance can likely be ingested by a system, to some level of granularity or for certain risks" then checking that you cannot have more than 1,000 authors is validation. Lets call this "capacity validation".
By the way, if validation and feature extraction are both merely transformations of the input document, what do we call a system that takes an invalid document and transforms it into gobbligook? XSD!
Regards
Rick
** Without againsting its aptitude in other areas. Is it even fair to declaim that XSD is finest for closed systems that needn't fix or fudge dodgy documents, not one for vetting and dealing with untrusted or varied documents?