UnauthorizedAccessException exception in ItemAdded and Updated handler in event receiver

wish help you to fix your issue For event receiver fire ItemAdding and ItemAdded, you need to change elements.xml as follow:

    <Elements xmlns="http://schemas.microsoft.com/sharepoint/">   
   <Receivers ListTemplateId="10002">
      <Receiver>
        <Name>SharedItemListEventRecieverItemDeleting</Name>
        <Type>ItemDeleting</Type>
        <Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>     
        <Class>ListDefinitions.ListsEventRecievers.SharedItemListEventReciever.SharedItemListEventReciever</Class>
        <SequenceNumber>10000</SequenceNumber>
      </Receiver>

     <Receiver>
        <Name>SharedItemListEventRecieverItemDeleting</Name>
        <Type>ItemAdding</Type>
        <Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>
        <Class>ListDefinitions.ListsEventRecievers.SharedItemListEventReciever.SharedItemListEventReciever</Class>
        <SequenceNumber>10000</SequenceNumber>
      </Receiver>

     <Receiver>
        <Name>SharedItemListEventRecieverItemDeleting</Name>
        <Type>ItemAdded</Type>
        <Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>     
        <Class>ListDefinitions.ListsEventRecieverSharedItemListEventReciever.SharedItemListEventReciever</Class>
        <SequenceNumber>10000</SequenceNumber>
      </Receiver>

    </Receivers>
 </Elements>

wish helps you Problem is that In Document library event handlers during Item Updating also checking that Document is it in Check In mode or Check Out. That's why it is called twice.
You should put your code in

 public override void ItemUpdating(SPItemEventProperties properties)
  {  
    base.ItemUpdating(properties);
    if (properties.AfterProperties["vti_sourcecontrolcheckedoutby"] == null && properties.BeforeProperties["vti_sourcecontrolcheckedoutby"] != null)
     {
       //do stuff
     }
  }