The purposely 'misunderstood' Stoeckle quote:
"the extant population, no matter what its current size or similarity to fossils of any age, has expanded from mitochondrial uniformity within the past 200,000 years'
They're talking about the frequency of genetic mutations in a particular gene in the mitochondrial genome over the last 200,000 years in modern species, not the original of genes altogether. Variations of that gene within a species, as expected, would be far less been compared to others species.
Although that would depend also on population size and genetic diversity for given species. Something like a cheetah which went through a genetic bottleneck and thus exhibits less genetic variability would of course show far less.
According to the misinterpretation you refer to, cheetahs have only existed for 12,000 years, which of course we know is untrue. But even 12,000 is twice as long as Earth supposedly has existed according to your mythological worldview. 200,000 years - well, you do the math.
Lungfish don't have lungs? Nice to know. I guess that means that the lungs of coelacanths and birchers aren't lungs as well. I should jot that down lest I forget.
Mudskippers are gobies without swim bladders, so nothing approaching lung function in that regard. Specialized structures in their mouth and gills help facilitate breathing out of water for them.
Some species of cetaceans have vestigial pelvises. That's because they no longer need legs to be attached to them, but they're not totally gone quite yet.
There are cultures that have flood stories, they happen all the time. If you were here in America you might have heard it on the news yesterday, occurring in Kentucky. Some are even bigger than that. None have been worldwide nor at the same time.
Research is key.