I add my own Visual Composer element to manage my first question.
When the element is added in a page with a valid form number, the form is added to the footer of my website. The footer html code is generated by a function copied from your dhvc_form_popup function.
For the second problem, I have to re-order one element in Visual Composer form editor and save the form to see the Recipients field.
I found the problem alone.
In fact “Sender Email” was not correctly configured. It must be only an email address. My client configure an email address with the sender name.
