>just wish there was a better way to debug xpaths that can't be matched
First: don't try to use the browser as a development environment. It's the worst possible environment for debugging. Use Stylus Studio or XML Spy, or just a text editor and command line XSLT processor such as Saxon.
Second: The advanced solution is to use schema-aware transformations with XSLT 2.0. See
http://www.stylusstudio.com/schema_aware.html - the idea here is that if the XSLT processor knows about the schema for your source document, then it can detect invalid paths at compile time.
Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference