the problem is that you have create a separate page for the form with univeral email on it and you are using include() to add that code to another page in the body.
this causes a problem becausecode that is supposed to be above the doctype of the page is now inside the body of the page.
Basically, the code that is performing the redirect:
must come before any HTML on the page, but by using include to add the form inside another pages body, it is now inside the HTML which causes the headers already sent error.
instead of using includes, you can create a full page, that includes the doctype, html, head, title and body tags, add the form and universal email to that page, then use framework builder to add that page to another as a plugin.