Get a good alarm system that monitors the perimeter of your home with door and window sensors, and motion in key areas. This is to alert you of an intrusion when you are home so you can escape. It serves no other purpose. So build it with that in mind. (Of course you can add fire and co2, water leaks, and other peripherals, but these are secondary).
When nobody is home you have insurance to cover your material possession. Nothing else matters. Your alarm system is useless here and will not deter or stop anybody who wants in.
Cameras are helpful for intel after the fact or just to be better informed about what is going on when you are not around. In 4 years I have gone back to look at footage maybe 5 times. They also help to check in on things when I'm off site, though. Such as checking to see if that garbage cans were left out,...
Dont forget physical security - a good security expert can walk around the outside of your home with you and point out vulnerabilities, like ladders stored in your back yard, easily breached entrances that need better nighttime lighting, etc.
In the end, a big well trained dog and an escape plan are your best means of defense.