Yes. When you add a rule to a button or question, you can specify which workflow tracks you want the submission to be associated with.

Use the View Reports link on the FormFlow - Forms page to see the form's submission status. When the form has a Submitted status, payment was successful. If the status is Payment Pending, payment has not gone through.

One way to check that data points are working properly is to add an email to the first stage of the Workflow track. This email should be sent to yourself on the "OnAssignedToStage" event. In the body of the email, include the tokens for any mapped data points. When the email is sent, it will show if the values you're expecting for each mapped data point are being seen by Workflow.

Not at this time.