1. Community core change was due to an earlier patch that allows a person to register as a user.
2. Deleting an acs-object would fail if the object specific table didn't exist. acs-objects and the content repository shouldn't require type specific tables be named when you extend a type, this is a temporary hack which acknowledges that folks have been cheating by name non-existent tables. Since I plan to remove the restriction anyway, this is not a big deal.