the Chinese troops that ACTUALLY CONQUERED ANOTHER SOVEREIGN NATION

Tibet is Chinese territory, so your point is invalid there.

Secondly, what exactly were the PLA retaliating against?

Reclaiming lost territory. Here's a map of the Qing dynasty. http://theqingdynasty.com/thecontent/images/2014/02/Territories%20under%20Qing%20Dynasty%20Rule.jpg

China had every right to reclaim Tibet as it had previously been under Chinese rule for hundreds of years but they temporarily lost control of it for ~30 years.

After all, I would have been taught my whole life that foreigners are to blame for everything bad in China,

Opium wars? They started it first and that's what began the xenophobia in China.

and everything good in China is the result of the great people's government of China in the person of the CCP.

Um lol no

I'm Canadian, I have access to the whole internet, I have always been encouraged to look things up for myself and find things out for myself and make up my own opinion on things, based on facts and logic, so my whole upbringing and education is completely different from the average Chinese person.

I have access to the "whole" internet too. I studied the Boxer Rebellion on my own and I reached the conclusion that the atrocities committed were unjustified and only helps to amplify xenophobia.

And when the 'rebellion' (a total misnomer by the way, should basically just be called the 'Boxer Attempted Massacre of All Foreign Nationals With the Full Complicity of the Qing Dynasty Government' but I guess that was too long for the history books) fails, I would not be surprised at all that said troops would engage in revenge looting, pillaging, etc.

Oh it was a rebellion alright. A rebellion against foreign domination in the China. Either way, rape, pillaging and murder is not acceptable regardless of the prior events.