Virily has been magnanimous in letting us edit published posts which is a good thing. Sometimes one sees howlers that are not noticed before publishing no matter how careful one is. Previewing and playing the quiz by the one who creates it also helps but enough is not enough.
Sadly there is the possibility of misuing this feature as Admin will not see it before it is republished.
Users therefore could only perhaps edit those posts that have just been published to edit errors if any and not the old ones as, if the old ones are edited they reappear as new posts.
Should published posts that are subject to edit be approved by Admin even if they come from verified users?