I don't consider them as worse than Nazi Germany, but I consider them as pretty bad.
The massacres and famines in India comes to mind.
The wars in China to keep selling them opium.
And the fact that Nazi Germany had to hide the genocide from the general population, but when a Britiah military officer massacred civilians, they were bailed and cheered on by the general population is a nuance to the idea that the British Empire was better in every regard.
And concerning population collapse, it's possible for a population to disappear if there's under a thousand isolated people. Disease, inbreeding, loss of crucial knowledge, climatic change, extreme weather, are all existential risks that a small population are exposed to.
Taiwan keeps those claims and this official name because otherwise it would be perceived as declaring Taiwan as a sovereign state, and that would anger China. Such symbolic moves are not seen as worth the risk of Chinese agression by most, or a large part of the Taiwanese population.
Preferably Catholic? Are those Europeans not aware that Europe has been cut in 3 between Catholicism, Protestantism and Orthodox Christianity since hundreds of years?
Especially if you consider the late 60s, which was an incedible cultural phenomenon, maybe unparalled since in innovation.