No, not currently, because the lastedit field is never updated; it's always the same as the creation date/time.

They should, especially if a change is implemented to keep lastedit up to date.

Right on!

I don't know about everyone else, but I don't see much value in a "Most recent spelling and typo corrections in nodes" page.

The site was built around the idea that new content goes into new nodes. Trying to change features of the site to work around ideas like "/msg me if someone updates a reply to one of my nodes" and "show me the most recently updated nodes" etc. just isn't going to scale. Most updates are currently (and should continue to be) quite minor updates, and as such should be of little interest to the majority of visitors. We could add a "this is a significant update" checkbox like we have for homenodes but the one we already have doesn't work well at all.

So the better route is to continue to discourage major updates to nodes, that is, to encourage major updates to happen via a new node (or at least be accompanied by a new node).