Would it cause less confusion to use adaptation exclusively to describe stable genetic changes over time?

It's kept this way mainly because "evolution is both a theory and a fact". Let me explain: microevolution has been proven. There's no question about that. Microevolution represents small changes in genes, which proves there is a viable mechanism for evolution. This kind of evolution is the kind the Catholic church acknowledged not too long ago. That's the fact portion.

Macroevolution is the portion still up in the air. It has not be proven or even observed. There is a mountain of evidence to support it and a viable possibility of it occurring, but there is no 'silver bullet' proving it beyond a shadow of a doubt. As anyone in the scientific field will tell you, if you can't silence every legitimate critic of your theory, then it's still a theory.

Three off topic additions: 1) don't cite Wikipedia for academic purposes 2) while I have nothing against the Bible, Christianity or religion in general, using it's writings as evidence is not a legitimate means and 3) your argument is overly wordy in a way that biases the case to your side by limiting the expression of an answer

Adaptation is not entirely genetic.  Genetic adaptation is evolution, but there is also physiological adaptation to an organism's environment such as breathing rapidly after exercise.  There is also behavioral adaptation to one's environment,e.g., going inside when it is raining.  

Using the word adaptation instead of evolution is just misleading.  It suggests that all of the physical evidence for evolution by natural selection is somehow wrong because it is contradicted by a few lines in a book that was written before people invented science to answer questions about the world.

"...facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts don't go away when scientists debate rival theories to explain them... Moreover, 'fact' doesn't mean 'absolute certainty;' there ain't no such animal in an exciting and complex world... In science 'fact' can only mean 'confirmed to such a degree that it would be perverse to withhold provisional consent.'""Evolutionists have been very clear about this distinction of fact and theory from the very beginning, if only because we have always acknowledged how far we are from completely understanding the mechanisms (theory) by which evolution (fact) occurred. Darwin continually emphasized the difference between his two great and separate accomplishments: establishing the fact of evolution, and proposing a theory--natural selection--to explain the mechanism of evolution."
Evolution as Fact and Theory
http://www.stephenjaygould.org/library/gould_fact-and-theory.html

The huge explanatory success of evolution comes not only from the empirical certainties of population genetics (as you point out these cannot be denied) but from the accumulation and integration of ALL the evidence supporting ALL aspects of evolutionary biology: population genetics, natural selection, speciation, modification with descent, etc.

Adaptation is a part of evolution and has been directly observed. Speciation is also a part of evolution and has been directly observed. Natural selection is also a part of evolution and has been directly observed. And the same goes for epigenetics, lateral gene transfer, beneficial genetic mutations, viral induction, transposable elements, gene duplications, transitional forms, homologies, symbiosis, etc. And we can?t forget supporting data from other disciplines: geology, chemistry, physics, astronomy, etc. In fact there is no scientific data that disputes the fact of evolution. If science is to be compromised for Biblical literalists by ignoring most of our accumulated scientific data then it?s no longer science, it?s a lie.

For more see:
Why Evolution Is True by Jerry Coyne
http://books.google.com/books?id=zOMNfAX-oLEC&printsec=frontcover&ie=ISO-8859-1&output=html