I would remove the email steps from the Forms process design and would rely on the workflow (started by forms) to email the acceptance (and completed pdf). Right click in the white space of your workflow and go to "View Properties".
Make sure your workflow is set to be started by Laserfiche Forms.
You can add an attachment to your email, and it could be the output from the "Fill Out PDF form" process. Make sure to set the properties on the attachment to pdf or it will email a link to the doc instead of the pdf.
Also, you can save a copy of a workflow to troubleshoot with. That way you preserve the original (just in case you want to go back to what you had). Same with Forms.