So what you're describing is intelligent design, as opposed to evolution via natural selection.
Um, yea.... You understand there's a distinction between "naturalistic" and Darwinian evolutionary theory, right? If the thetan lizard people, should they prove to exist, and were responsible for guiding, initiating, or messing with our evolution that would still provide a naturalistic, not a super-natural explanation--which would not obviate Darwinian theory; it would only show that evolution was not confined to the planet earth, as we had originally thought. The thetan lizard people had to come from somewhere, and, being naturalistic, would be subject to investigation by science, including, most likely, evolutionary biology. Hence my original prediction that got your motor going: that naturalistic ID will probably be swallowed by Darwinian Evolutionary theory without much distortion, should ID prove to hold water.
I think we're coming to the crux of the issue. Most people have a different understanding of what Darwinian theory is than you do. His theory is based on natural selection. That phrase was coined specifically to distinguish it from the type of selection that gets used in, say, breeding dogs.