Task Requests with EWS

I am trying to use EWS to retrieve the properties of task requests. I cannot seem to find a defined object such as MessageType for task requests and am therefore being forced to use the base ItemType to retrieve properties. The problem with this is I cannot get sender and recipient information. It offers me a DisplayTo property which contains only a string with the name of the to recipient. 

My questions:

1. Is there a better container for TaskRequests then ItemType?

2.  Is it possible to query EWS with a recipient name and have it return the email address? or visa versa?

Thanks in advance!