Is it possible to create some kind of submission form and a pseudo "inbox" for articles that all registered users can view?
The code to allow something close to that in MediaWiki exists, is available just for the asking, and could be adapted for CZ. You can see it at work at WikiHow--the folks there developed it. Go to any article, say,
http://www.wikihow.com/Fish-for-River-Trout, and scroll down to the bottom. You will see a link "Thank the Authors". This goes to a page where one writes a message that then goes to each of the main contributors of the article (that's another thing that could be added--you can view that at the bottom of the page there as well). The messages then aggregate at a special page, called "Kudos", for each author. The code that names the authors and allows reader feedback are dependent.
I am not sure we should implement it--maybe we should, maybe we should not--but the ability to do it is there. One issue is that we'd really not want to receive anon IP feedback (which is what all of it would be) on anything but approved articles, so that would mean writing code or, perhaps, placing all non-approved articles on a draft subpage. One good thing--and this is a major thing that would incline me to support it now, where I formerly argued strenuously against it--is that
none of the comments would need to be moderated (meaning this would give constables no new tasks), since they are only viewable to the specific authors of the article. Someone could cuss the authors out and the outcome would be no greater than receiving a spam message in one's email inbox.
Again, however, naming principle contributors to an article through the mechanism mentioned above, and this anon IP feedback system to them, are dependent. We'd have to decide on the former before the latter, or come up with something other than adapting this code from Wikihow to allow the feedback. I very much think CZ should adopt the author attribution system, for reasons I've spelled out elsewhere.
