i have a huawei phone and can watch all these topics, on youtube, I don't plan on visiting china anytime soon
Huawei
Tyler Ross
Zachary Ward
American, Chinese, Russian, doesn't matter. If it's consumer hardware then its botnet. Only difference is which nation get first dibs on your contact list and porn collection before the other nations discover a hack for it.
Brody Torres
kai feng
Robert Davis
You can't know. Same for any other product. Being realistic you should assume every electronic you own is bugged, but most of it won't be activated on you since you're not important enough to risk detection.
You can visit China even if you bring with you books on all these topics (they may confiscate them though). Chinks are pretty clever with their censorship, they don't care what foreigners can access and even have different filters for different parts of the country.