[mpumas]

Question 1-It is not safe to shift into Neutral whenever the car is moving. This practice is called free wheeling and in many states is illegal. Also you should always let the car's engine compression help you slow down to a stop. Your brakes will last longer.

question 2-Sometimes you may accidently shift into Neutral while the car is moving. It doesn't cause any major problems unless you leave it in Neutral for a period of time for the same reasons noted above.