There is absolutely no way of anwering this question with a definitive answer. Everything depends on too many factors. Is the vehicle used for primarily highway miles, city miles, or mixed driving? The weight that the vehicle normally carries (lightly loaded or heavily loaded)? Is the driver heavy on the gas and brake or economical? On-and-on. . . too many factors involved to give a "normal" estimate.
There is no magic number as to how often you should change your brakes. Brakes will wear down differently depending on the make of the brake and they will start squeaking so you know that you need to change it.
Depends on how many stops you make each year. There is no set time or mileage. You inspect them periodically and replace as necessary.
every 30k miles
No but heavy braking will
every 3 years!!
Rear brakes do not have to be replaced too often. It's really hard to tell without looking at it. What you can do is to replace front brakes and test drive it, if you feel that your car brakes works just fine you do not need to replace rear brake shoes.
They need replaced when they wear out.
You should check your brakes at least one time each year. You should also check them whenever you have your tires rotated.
How often brakes should be changed depends on the type of brakes in the vehicle and the use of the bakes in the vehicle. However, the general rule is every 10,000 miles.
Although there is no set on how often your brakes should be replaced, I would just pay attention to your car. When you notice something wrong, I would call your auto body shop.
Not often if there tarting to wear and tear you should replace them.
It depends. High quality brakes can last a very long time if you drive your car properly and do not rabbit drive. If they are squeaking, you should have them checked out.