Facebook SDK Doubts

Hi everybody. I’m implementing the Facebook sdk for Unity and i have some questions and issues.
I used facebook plugins before and the Graph API but i have some questions about how can a i get some information.

First:
I want to load the friend list and i tried with this:

FB.API(“me?fields=id,friends”,Facebook.HttpMethod.GET,FBCallback);
and
FB.API(“me/friends”,Facebook.HttpMethod.GET,FBCallback);

private void FBCallback(FBResult result)
{
Debug.Log(result.Error);
Debug.Log(result.Text);
}

The first one it gave me nothing, no data, nothing. The secondone returns data:[ ] empty
Any idea?
Edit: This code is returning me only people who has my app installed. But what should i do to get all of them?

My second issue is:
The login is divide it in two parts, read and post permissions. First read permission and then post. The question is, How do i know that the user might cancel post permission?

Another thing is:
I can send apprequest, also i can parse the request_ids, but how can i know what is each request_id (life or money example) and how i can delete them!! I’m watching like 20 threads with different things and nothing works!

Thanks!

Any ideas?