This sounds like an awesome hack, I can't wait to give it a test drive!
The thing that I'm wondering about is how difficult it would be to exclude user's edits from being copied into the recycle bin. With the number of users on a large board, a recycle bin is going to start filling up mighty quick.
Keeping copies of posts that an admin, mega, or moderator deletes or edits is a good way to ensure responsible judgement calls and accountability. Personally, its not important to me if a member decided to edit his/her own post.
Anyhow, sorry about the critique-- this really is a good idea. Thanks!