Hi Chris
You're right, if you don't add these fields to the schema, you won't be able to query those fields directly.
However, why would you need to query fields such as AWS_CHOICE? As far as I'm aware, they are populated automatically when the form is rendered by Form Manager, and any relevant data is extracted from these fields and used to govern the route that the workflow engine executes, the user who is logged as having completed the step, etc. I've always treated these as "internal implementation" fields that I should not/need not directly modify or read.
What are your use-cases for directly querying these fields?
Getting back to the original question, there is another way to start a process by emailing a form. Create a looping master-process that uses the EmailReceiver qpac to pull the form from a POP3 server, extract the attachment and other details, and then use the chain qpac to initiate the actual process. While this doesn't use the built-in capabilities of the workflow server to process incoming emails, in some respects, it is a simpler solution where you have more control over the operation. Just a thought...
Howard
http://www.avoka.com