Regarding your source for the claim of Mao as a sex abuser, The Private Life of Chairman Mao by Li Zhisui, here's what Wikipedia has to say:

Several people have questioned the authenticity of the book. Li's memoirs were not based on original records or personal diaries. During the Cultural Revolution, he burnt all of his original diaries and, as such, the book was based on restructured memories which might be wrong or fallible as Li's collaborator, Anne Thurston, admitted.[14] Historian Frederick Teiwes accused Li of being "anti-Mao".[15] According to Tai Hung-chao, who was the translator of the book, Random House, the company which published the book, wanted to add more "juicy bits" to the book such as Mao's sex life in order to attract a larger readership.[15] Li disagreed with this line of approach, but eventually gave in to it.[15] A statement protesting that many of the claims made in Li's book were false was issued soon after its publication, signed by 150 people who had personally known or worked with Mao, including Wang Dongxing, Li Yinqiao and Ye Zilong.

The about this site section of factsanddetails.com is also especially concerning:

I am not professor or an expert on the subjects I write about but I have done a fair amount of reading about them. I try to use good sources (see below) and have been doing what I am doing—collecting and organizing information and facts— for some time and feel I have developed some skill at it. The text is written in factoid style generally using language found in travel guides, magazines and newspapers rather than academic journals. I don’t have footnotes and bibliographies but I often list sources at the end of the facts or under the first fact under each subheading. When a source is not listed the information: 1) can be taken to be a generally accepted fact (often seen in at least two different places); 2) has been arrived at through observation (direct or second hand through other sources) or by common sense; or 3) was taken from a newspaper or magazine article that didn’t attribute it.

In other words, hearsay is totally fine and allowable information.

When I started this project in the 1990s I used mostly print sources such as the New York Times, Washington Post, Los Angeles Times, Daily Yomiuri (a Japanese newspaper), The Times, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, U.S. News and World Report, The Guardian, Atlantic Monthly, Archeology magazine, Natural History magazine, news services used by these periodicals such Reuters, Associated Press and AFP, information from national tourist offices, tourist brochures I have picked up from places I have visited, Lonely Planet Guides, other travel guides, Compton’s Encyclopedia and various books and other publications.

In other words, near-exclusively western media, with no alternative perspectives whatsoever.

When I started this project I was living in the Washington D.C. area and called every embassy and national tourist office and asked them to send all the information they had—and started with that. Later, I collected the newspapers, magazines and books that I listed above and every few months spent an entire day cutting them up and putting them in piles based on country or topic and put the piles into boxes with previous piles, ending up with about half a room full of article-filled boxes. The piles of articles used so far for China and Japan alone, when added all together, would probably exceed three or four meters in height. It is a crazy system I know but is ultimately easier, more comprehensive and reliable than relying totally on Google searches.

In other words, the site maintained lived in the heart of the US, and found sources directly from the US state department.

As for Taiwan, their own self-described title is the Republic of China, who do not claim independence from the mainland but instead sovereignty as the self-percieved legitimate government of the mainland as well as Taiwan. Saying "Taiwan is not China" is actually against Taiwanese identity. The question isn't whether or not Taiwan is Chinese, but whether the government in Taiwan or Beijing is the legitimate government of China.

As for Hong Kong, as of 2019 (the latest polling) only 17% want independence from the mainland. Hong Kong was already freed from British colonialism, and has now been returned to China as the era of colonialism has ended.

There's no actual polling data concerning Tibet that I can find. However, prior to the intervention of the PLA, Tibet was a feudal slave society with rampant sex abuse.

The Tibetan serfs were something more than superstitious victims, blind to their own oppression. As we have seen, some ran away; others openly resisted, sometimes suffering dire consequences. In feudal Tibet, torture and mutilation — including eye gouging, the pulling out of tongues, hamstringing, and amputation — were favored punishments inflicted upon thieves, and runaway or resistant serfs. [22]

Journeying through Tibet in the 1960s, Stuart and Roma Gelder interviewed a former serf, Tsereh Wang Tuei, who had stolen two sheep belonging to a monastery. For this he had both his eyes gouged out and his hand mutilated beyond use. He explains that he no longer is a Buddhist: “When a holy lama told them to blind me I thought there was no good in religion.” [23] Since it was against Buddhist teachings to take human life, some offenders were severely lashed and then “left to God” in the freezing night to die. “The parallels between Tibet and medieval Europe are striking,” concludes Tom Grunfeld in his book on Tibet. [24]

In 1959, Anna Louise Strong visited an exhibition of torture equipment that had been used by the Tibetan overlords. There were handcuffs of all sizes, including small ones for children, and instruments for cutting off noses and ears, gouging out eyes, breaking off hands, and hamstringing legs. There were hot brands, whips, and special implements for disemboweling. The exhibition presented photographs and testimonies of victims who had been blinded or crippled or suffered amputations for thievery. There was the shepherd whose master owed him a reimbursement in yuan and wheat but refused to pay. So he took one of the master’s cows; for this he had his hands severed. Another herdsman, who opposed having his wife taken from him by his lord, had his hands broken off. There were pictures of Communist activists with noses and upper lips cut off, and a woman who was raped and then had her nose sliced away. [25]

• Friendly Feudalism: The Tibet Myth