Hi there, I am a camera expert, specially with a rapsberry pi , built 3 raspberrry pi camera projects recently, they are in testing phase now . Did many video chat projects including pi in last 18 years. Please send me a message. I can build verifiable secure systems (will survive all attacks) , on embedded linux , web server etc. The project requires more than what you see now.
Your requirements are mostly around cameras, but there are free modules on internet to detect people, number plates etc., vpn as you may know doesn't require any software development, it is just installation.
Can you please send me a message so that I can give you more details and show you around.
I worked with a company for 6 years only making video projects, streamers ,codecs, bandwidth management , compression , storage , stamping , modifying , bandwidth detection , security , did everything.