I don't see why the articles on the main page aren't editible, it seems to me that it wouldn't be abused any more than the current editing feature is.
Adding further addenda (addendums ?) just adds clutter where editing the original would have sufficed. IMO.
As for using the preview, well this node doesn't seem to have one.
Baldrick, you wouldn't see a subtle plan if it painted itself purple and danced naked on top of a harpsichord, singing "Subtle plans are here again!"