Ted, I'm still trying to delete my outdated posts but I only seem to succeed in removing my comments in the post. Help please!
Outdated posts can't be removed by members. You may remove all your comments in a post as you've done then add a new post indicating the thread is outdated and directing viewers to an updated thread. This is best all around result for search engines.
Admins may remove outdated threads posted by a member but admin requires list of url's of outdated threads. Removing threads like this is not the best answer as google and other search engines still retain the original post and when someone clicks on the search result of the outdated thread the visitor will be shown page is missing or is a 404 error. This doesn't benefit member whose post was originally stored by search engines. Over time the search engines will eventually removed outdated and removed threads from their search results, but it is often better to use an outdated thread to point to an updated thread and explain why.