While they are young they need to be socialized extensively, and introduced to every situation they can possible end up in later in life. This is to make the dog calm, tolerant of new places and controllable.
Most of mine grew up in a local dog park. The "regulars" in there can still meet and play off leash. But you are absolutely correct - it is a HUGE responsibility to live with one of these dogs, they are sertainly not toys or pets.
The range in sizes ... Caucasian Ovcharka is not just a single breed. It is a breed group. Mountain regions of Caucasus were pretty isolated from each other because of impossible terrain. So each region developed and maintained the dogs to their liking and using available breeding stock. They are very different looking - steppe versions are dryer and taller, mountain versions have more mass to fight bigger predators and keep warm at night... there is even a legend that the color of sheep in the flock dictated selection of dogs left in a litter - they had to blend in so predators two- or four-legged will not know that dogs are on duty (COs do not have their own dog smell, like german shepherds forr an example - they smell like whatever they live in). Supposedly, this is why pure white Caucasians are so rare - white sheep was very expensive and luxirious, and not too many people had them. But one thing that unite all of them is the intelligence, working ability, strong character, suspition of strangers, devotion to family and flock, ability to make their own decisions depending on situation, ability to live on a very minimal food and water amounts, high pain tolerance and so for...
Favorite Russian "version" of Caucasians, written into latest standard is the Georgian Nagazi - large, strong, impressive dogs. But there are others.
Here are pictures of some of my dogs - well socialized wit people and animals.
two year old intact male Arzach - but he is an exception to the rule.

We start early - 8 week old Balue and Nala.


Arzach and young Balou




Balou since then became more protective and do not go off leash in public place any more.