Good points and illustration. I think that there is no true need to be able to empathize with alien intelligence in a narrative. Goodness knows I have trouble empathizing with plenty of human characters… Hierarchy of Foreignness was even a thematic element in the Ender books.

Have you read A Fire Upon the Deep by Vernor Vinge? I remember it doing a pretty good job of imagining polymorphic sentience and civilization churn.