If it is a guard dog it guards property, that is useful.

A guard dog guards everything behind your fence or in your house, a protection dog will protect you outside your property, a watch dog will give alarm when someone enters your property. A rottweiler is an ideal guard dog.

A watch dog is the same as a guard dog. They guard a building of some sort for robbers, intruders, and mailmen.

Yes. You could die or get seriously hurt from any guard dog attack.

From what i know, you have train them to be a guard (Requires lots of patience) Hope this helped!