I applied it when I was doing my undergratuate and it was really a while back.  My EAD got approved and the only document I sent was the Nepali Rs Vs US dollar chart showing how the US dollar value has gone up Vs Nepali Rs since I first came to US.  To my suprise I was not asked for any more documents.  If you application is denied than the only thing you'll loose is your application fee.  Don't worry, if you have a good case and ducments you can get it.