As a suggestion, it might be helpful to have the "Please do a SEARCH before posting" message at the top of the form (on smaller screens the message below the submit button isn't immediately visible).
This way, the user will actually see the message before writing or copying the Magna Carta in the form fields.
It is simply human nature to want to post a message after entering it into the form fields especially considering that the user doesn't want to lose that information he/she just typed in based on the possibility that the question is already answered.
This won't eliminate all redundant posts, but it may encourage some to "Search First."
