I believe admins are the only ones to have access to the edit history of a post, and I believe it's not as easy as it sounds to look at. Moderators can't see the edit history AFAIK, and implementing something like this would only be useful in certain scenarios where other times it will just be useless. I get annoyed when people on Reddit edit their post, and state "edit: a word".
Can admins see editing history of a post?
Yes, though it's a bit of a hassle.
There's currently no history of profile fields, though, so you definitely can't rely on your signature or anything like that.