It is certainly true that there is a lot of disagreement among the experts on the details of human/ape evolution, and one really does have to draw one’s own conclusions by looking at the data. And while I agree in a very general way with your conclusions, I think you have significantly overstated the case.
Lucy had the cranial capacity of a chimp, and presumably the intellegence level of chimp as well. (Was your retriever analogy just a tongue-in-cheek exageration?) There is also ample evidence (limb ratio and finger shape) that her kind spent a good amount of time in the trees.
There were also hominids (like A. robustus) who appear to have been specialists along the order of gorillas. And while gorillas can be considered specialists, chimps are much more generalists, so lumping them together in that sense doesn’t really square with reality.
It is highly unlikely that chimps and gorillas evolved from an upright hominid-like ancestor. Since upright posture is the hallmark of our line, it doesn’t make sense to say that “apes evolved from men” even if you use “men” to mean very primitive proto-men. It is certainly possible (I think likely) that humans, chimps, and gorillas evolved from an ape that was more of a generalists than either chimps or gorillas, but to say that the common ancestor was more human-like than ape-like doesn’t hold up to scrutiny. The common ancestor was probably more chimp-like than anything, being a quadrupedal, tree dwelling ape with the cranial capacity at or slightly lower than a modern chimp.
It might be that the bonobo is a better candidate than the common chimp, certainly the genus Pan looks like the best model for the common ancestor.
I’m leaving Orangs out of it, as the timeline for their split from the human/chimp/gorilla line puts them in a unique category.