Reading this - I think you may not understand that there is no need to edit XML - in fact it is very difficult to do. The graphic designer will actually allow you to change the type of work item, add new fields, change workflow, rules, etc.
The only reason for changing XML is a bug in the process editor (a tool that a graphic designer provides). I made extensive changes to the types of work items and had only one instance where I had to change the XML.
fuzzbone
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