Hi Mark
Re my question 1: What I was suggesting is that vBulletin display a brief message upon submission of each post that the user has just 10 minutes should they wish to edit their post.
Re my question 2: The Edit button disappears at some point, so there must be some trigger for that, so why doesn't vBulletin do the logical thing and make it disappear 10 minutes after the post is submitted (for after that time the button is effectively useless even though the software allows the user to click it and write a post that then cannot be submitted - which is dumb!)