thedriver,
may I ask you what do the Commands execute retrieving Notifications from Proxy?
A Proxy or a RemoteProxy as a part of a Model sends a Notification to notify all interested Views when its data has been changed. That means all Mediators can listen to these if they are interested using its method called "listNotificationInterests" and can handle it using its function called "handleNotification". For this issues you don't need a Command and it might be a uncommon way to update a Mediator (View) from a Proxy (Model) using a Command (Controller).
If you want to manipulate other Proxies after receiving a result in your RemoteProxy it might be a way using a Command to map the Notification and to manipulate the others Proxies. But you could manipulate a Proxy from the RemoteProxy directly using "facade.retrieveProxy(AnotherProxy.NAME) as AnotherProxy;" as well if you have to solve this issue only once. One way to reduce the number of Commands.
For reducing the number of Notifications: If there a need to make a difference between Notifications for all faults? As you've already written you could use only a Notification called "ApplicationFacade.GET_DATA_FAILED" to handle all data errors. To show different error messages (e.g. using a PopUp) use the Notifications "body" object holding these messages.
For handling different results such as getting new user data or updating user data I would use different Notifications as well. So any interested member has the choice to listen to it or not without distinguishing the result.
@Cliff: As I see, you've already answered. Sorry, my post in English needed some time
-sectore