BUMP: This is not a dead request. I\'m still hoping to get a solid answer from someone at Facebook or anyone else. Thanks.
Revised Inquiry: I don\'t know if I\'m not ask
The definitive answer was provided by a Facebook developer here in response to my bug report. The resolution is that this is By Design. This relates to the note by @noah-callaway that there's probably some app-specific data in requests that should not be available to other apps.
This is a shame, in my opinion, because as Facebook is all about sharing data among friends, I think it adds a dimension to the ecosystem when apps can share (limited and reasonable) information among one another.
Thanks for the responses!
You are right, you need the app_access_token and not the user_access_token.
I think the FB documentation has an error.
You need to make a graph api request to get the apprequests connection for a user. See the current documentation here: http://developers.facebook.com/docs/reference/api/user/.
In the Connections table, the documentation correctly notes that you need an application access token to retrive the requests to that user. There's a bug in the documentation under (http://developers.facebook.com/docs/reference/api/user/#apprequests) that claims you need a user access token. This is incorrect, and (as you've seen) will return an empty list of requests.
Requests sent by an application are only visible to the application. The user can't see or delete these requests (though they are able to hide the request). The reason for this is that the applications can put data into the requests (255 characters) that's never exposed to the user or other applications.
I don't think there's a way you'll be able to aggregate a user's requests from apps that you don't have an access token for.
What I have found out (before my question was deleted) was that you can't access requests with a user token, and app tokens can only access requests that app has sent (and I found that out myself in the documentation and playing with the graph explorer). Since I know there are iPhone apps and browser plugins for processing requests, I assume they are accessing the page itself and parsing the data (like scraping a site). The downfall to that approach is that on the request page only around 100 requests from each app are shown at one time.
(Unless some people have found a way that they aren't sharing...)