The edit and delete links vanish not long after a post is made. I've never bothered to research the exact duration, but I believe it's no more than 24 hours.

Edit: After some observation, it appears to be two hours. I don't want to be pissy about this, but this is what I was worried about in my other comment--you seem to be making this drastic change with no little thought to how it will interact with the systems and behaviors already in place.