I am not sure if I understand your question correctly.
Do you refer to related entities of a particular entity as "...the values with Null-able objects are not referencing...
entity has a collection
entities and a reference
to a Customer
entity. Here order.OrderDetails
are called navigation properties
By default navigation properties are not loaded when using WCF Plain Services
generated by Add OpenAccess
If you want to enable loading of navigation properties you should follow the instructions in this tutorial
Please let me know if I have misinterpreted your question or you need any further assistance.
All the best,
the Telerik team
Q3'12 SP1 of OpenAccess ORM packs Multi-Table Entities mapping support. Check it out.