While I generically agree with you, I think that "Assume any consumer cam oconnected to the NET will steal all your videos and info and send the IP adress, video stream, location info etc" is a bit excessive.
Recording all footage 24/7/365 of all consumer cameras in the world would generate huge data, plus you would notice the external access to your cameras by looking at the router data rate.
But yes, I do believe that agencies (US or China) could access the camera if they wanted or needed it.
On the other hand: "they" could enter your router/network/VLAN as well. Who knows what backdoors are left in the firmware of your router, access point or network card. Heck, even your computer's BIOS or chipset might have some low-level door open.
If we go on with maximum paranoid level, then we should realize that those same agencies can access our mobile phones remotely, including camera and mic.
Considering how many phones and consumer surveillance cameras are being sold and used, I think that automated large scale monitoring is not feasible due to the amaount of bandwidth, storage and CPU power required. Hence I do not worry too much. But when I want privacy, I make sure to switch cameras off.
By the way: with new electricity meters employed by the energy providers, the new feature to make remote readings for billings, can and will be used to monitor what you are doing. They could even measure what TV channel you are watching, considering that different luminosities have a relationship to the power consumption of the TV. Officially this is to best serve you and make extrapolation for power generation.
It is no coincidence that goverments and secret labs/agencies use special shielded rooms.
So, coming back to topic: if you are not too paranoid, a consumer camera for 30£/€/$ will do the job easy, convinient and cheap. The more paranoid you get with privacy and security, the more money your solution will cost and still you can never be 100% sure that "big brother is not watching you".
The best privacy is to not have any camera, as I already said.
Cheers,
Vitor