A couple of notes:
Q: Is there a plugin I can use to help test the data and text within a PDF?
You can also use the PDFBox library to read the PDF file contents programmatically. Here's an example:
https://community.smartbear.com/t5/Functional-Web-Testing/Getting-exception-while-trying-to-read-PDF-file-using-pdfbox-dll/m-p/85534#M19909
Q: Project scripting language - what would you recommend? C# or JScript? ...
Just FYI, C#Script != C#. If you want C#-like syntax use JavaScript.
C#Script is a (legacy) version of the (now legacy) MS JScript engine that uses square bracket syntax instead of dot notation, that is: object["property"] instead of object.property. It's a limited-purpose language, not a general-purpose one. C#Script should not be used for new projects.