Regarding the possibility of Chinese spying in your computer, many cases of CIA shenanigans kind of weaken the case for US developed software.
Huge difference. The Chinese government is a totalitarian regime. Its primary objective is the preservation of its own power.
Most other countries' governments have a primary objective of serving the people that elect them. Corruption obviously distorts this, but corrupt individuals act in private ways to increase their own personal wealth or power. They don't use the levers of government intelligence against individual citizens of other countries. It's not that they wouldn't if it helped them acquire wealth or power, but this would require a large conspiracy to achieve and typically doesn't confer much benefit to the corrupt party.
I don't much care if Germany or India or US government monitors communications for information on terrorist attacks, because I know they can't use it against me. In the US, at least, we have a judicial system with rules for presentation of evidence, where evidence obtained without a warrant or via certain other permissible means is simply inadmissible in court, and without a court conviction, I'm a free citizen -- free by default, innocent unless PROVEN guilty (the opposite of life in a totalitarian state). But they can still use the data acquired to stop terrorist attacks. I'm OK with that.
This is not to say I like the idea of any government monitoring me (I do not and avoid giving even my government info to the greatest extent possible), but there is a night and day difference between a democratically elected government's use of computer data and a totalitarian regime's. China, Russia, Iran, and North Korea have teams of people who scour the Internet looking for posts that could be harmful to their regimes and taking actions to discredit or diminish those posts.
Similarly, if you buy hardware or software from China, it is reasonable to worry that it includes an ability for China to take control of that device if it decides that to be in its strategic interest. Even if the US government has similar military objectives, the tech is not developed under the eyes of the government, so they (typically the NSA, not the CIA, but some overlap) would need to hack it the same as any third-party government or private entity. So, yes, the NSA may have an ability to hack every Cisco device, but if so, it's only because they are sitting on a zero-day attack that they discovered and are keeping it to themselves. For the Chinese equivalent, the government could require backdoors of all Chinese companies (who all exist only at the pleasure of the Chinese government), and there's plenty of reason to believe they do exactly that.