Hi,
First: If you use the submit by email button, only xml is available as a choice. Instead, insert a Button, browse to the Object tab, and you will find the submit tab. Submit to URL: "mailto:" This will open the email application. Here you can set submit as PDF.
The XML file can be read in a standard text editor, or a xml parser.
Second: I believe you can only save the forms using Acrobat. For Acrobat Reader, I think you must enable Reader Extensions to be able to save the form.
I hope this helps you.