I would suggest something similar to what
@ChaosConjurer said but instead, you can view the link and what-so-ever like you currently can at the moment.
The only
changes would be, the application is linked to your forums account so the system knows you have not meet the requirements thus not being able to submit the application.
Be it
x/
x messages ,
x/
x successful reports,
x/
x joined time etc.
The [
submit] button is visible but not clickable, it would state "
Have you met all requirements?" or "
Requirements not met"
[
requirements] will be a hyperlink to the requirement + explanation/guideline thread.