(a).On theoretical and practical grounds, DTD's are now understood to be a weak way to describe the schemata (small 'S') of XML documents. The specialists should argue about whether RDF or XML-Schema's (uppercase 'S') work better (or try each on for size) and if there is a compelling reason to have a DTD then derive one from the Schema.
I agree, and will use the W3C XML-Schema syntax to produce an XML interpretation of Kevins document. I'll refrain from using any complicated Schema features so at to not detract from the core discussion.
The debate in the developer community concerning Schemas is currently something of a hot topic [1].
I hope to be able to present something shortly.
Cheers,
L.
[1]. http://www.xml.com/pub/2000/02/23/xmldeviant/index.html