What are chinas rules about cameras in carry-on’s?
TSA doesn't care about cameras or camera bags in your carry-on. Those aren't a threat to the plane. As long as they fit, TSA will let you by. And honestly, TSA doesn't care if they fit. The airline will though. When you enter China, you will go through Customs (not TSA). They inspect your bags to make sure you're not bringing anything prohibited into the country. Food items are often prohibited (there are food import restrictions in all countries, not just China), which is why your brother had trouble. I don't know of any restrictions against cameras. They may very well want to see what types of images might already be stored on the device, so I would take it with a blank memory card. They do not allow you to bring in anything (images, videos, music, computer files) that might interfere - in their minds - with their culture or politics. https://www.travelchinaguide.com/essential/not-taken.htm
Okay. Exactly from what country are you departing from and to what country is your destination? (I will assume you are departing from the U.S. and traveling to China) I can only answer for the security aspect. It is fine to bring this camera with you as carry-on and recommended over checked baggage. https://www.tsa.gov/travel/security-screening/whatcanibring/items/digital-cameras When at the x-ray, you are likely to be asked to remove the camera from your carry-on and placed in the plastic bin with nothing above or below the item. https://www.tsa.gov/travel/security-screening (Look under "Carry-On Baggage Screening" and see "Electronics") "I know sometimes they can be a little suspicious with some things because they got super pissed when my brother tried to bring peanut butter with him and some MiraLAX." Actually, more like "mildly annoyed" since the restrictions regarding liquids, gels, and aerosol has been in place since 2006 and people still bring such oversized items in their carry-on rather than stow them in checked baggage. This in turn slows the screening process down. https://www.tsa.gov/travel/security-screening/liquids-rule As for China, I don't have any information on their rules regarding security screening or customs.