dphillips
Obviously there is not much QA vetting by an alternate person before the questions are deployed.
As to the question writing challenge: is there a way to know the potential question has not been written before?
To the best of my knowledge the vetting is performed by Steve Jones, and lord knows he has a considerable work load running this site. I believe at one time Steve had some volunteers assisting, but as work loads changed and other events in the volunteers lives cause them to gradually drop this task.
And yes you can review previously asked questions. Note in the page that is displayed after you answer a question there is a link just below the blue bar which contains the text "Questions from the achieve", beneath that is a link " << Older questions" Click on that, as I did today and before giving up (tired finger syndrome) got back to the QOD date Nov. 9, 2006 and had not reached the end.