There's a lot going on here, so I will go section by section.

1. Hong Kong

The scale of the violence against protestors is exaggerated, and much of the protests were directly funded by Hong Kong bourgeoisie and Western NGOs and States, like the US. Currently, less than a quarter want independence. This is because Hong Kong was a british colony and financially is totally enmeshed with mainland China.

2. Taiwan

Both Taiwan and the PRC claim legitimate rule to the entirety of China. However, Taiwan's historical background is as a runaway retreat for the Kuomintang, a Nationalist party that was at war with the much more popular CPC. Taiwan also serves as a staging ground for the US to exert pressure on the PRC.

3. Uyghur Repression

This is a topic I don't know enough about, and reserve the right not to speak. However, I will say that claims of "genocide" come from the fascist Adrian Zenz, and moreover travel to Xinjiang is open and freely permissible. In addition, Uyghurs were exempt from the One Child Policy, as all minority populations were. I cannot speak on the treatment within the re-education camps, however, as I have not done the research necessary.

4. Imperialism

When Marxists speak of Imperialism, they speak of Lenin's definition and outlining, which refers to a specific stage in Capitalism where Industrial and Financial Capital are exported to super-exploit for super-profits. These actions by the PRC do not constitute Imperialism from that standpoint.

5. Covering up

I am not aware of the CPC covering up or censoring discussion of these topics.