SSAS Multidimensional Model: Questions on Key Attributes

I have several dimensions whose key attributes (i.e. attributes whose Usage property = "Key") takes a really long time to process (because the dimensions are really big; some of them are actually parts of a fact table). To speed up key attribute processing but without losing any functionalities, If the key attribute, which is a surrogate key, is already ordered in the corresponding source table AND it NameColumn property is not set: 1. Is it still necessary to set its AttributeHierarchyOrdered to "True"? 2. Is it still necessary to set its AttributeHierarchyOptimizedState to "True"? I ask this because I think it should be its corresponding foreign key of the fact table that needs to be indexed, not the primary key of a dimension. Would the answer of the above two questions be different if its NameColumn property is set to a different attribute? For example suppose the attribute's KeyColumn property = "ProductIdx" but the corresponding NameColumn property = "ProductName", and OrderBy property = "Name"? Please advise.