Hi - SharePoint List forms don't permit custom code - thus qRules won't work with your list form, I'm afraid.
If you are working with a regular browser form, not a SharePoint List form, you can either publish directly to the form library if the Sandbox is running on your SharePoint install, or you can admin approve the form template.
Your second point - that the mapping tool does not accept XSNs - are you on the correct tab in the tool? You want the Define Mapping tab.