We currently have nintex workflow provide to me through sharepoint 2013. unfortunately I don't have access to nintex form builder or InfoPath.
are there any other ways to create a form?
is there a way to document the approval of a file without creating a form to attach that file to?
for example: a word document that requires it to be approved quarterly by 2 approvers.
In general you don't have to edit the approval forms - they work out of the box as Jan Eyres has already said. I usually only edit the approval forms if I need to request additional data to the approve/reject answers or if I need to add validation on the form.