BizTalk 2010 Path Validation in Custom XSLT for Maps

Question

We are developing a EDI application using BizTalk 2010 and Visual Studio 2010. Because of our complex requirements, we are making extensive use of the custom XSLT feature provided by the BizTalk mapper instead of the mapper GUI.

Although I find it much easier to implement the logic we need, developing in XSLT is cumbersome because of the lack of any sort of validation of the Paths in our XSLT files. We are getting our paths by copying the "Instance XPath" property out of the schema and altering them to be in the proper format. We sometimes make mistakes in this process and we don't know how to validate that our paths are correct.

Is there something we are missing or is there a tool that we can use to validate the Paths in our XSLT files against our input schema?