Ho to avoid fly away? And go crazy uncontrolled? And How long motor life Dji phantom 3 advanced to truly weak?

The motors will last a long time.
The P3 won't fly away but if you read the manual and learn how it all works you'll improve your chances of bringing it home every time.

just Dont lose eye contact with ur bird and fly safe .. and let other stay safe

Hello, here are some safety tips and you can check them :https://www.youtube.com/playlist?list=PL8-vxWY64sBOmkQQJ2KWNL-uRBZsP43-r

All good advise so far. Especially keeping in line of sight. Never loose orientation either and always make sure your home point is set and check it on the map before you take off as I feel,it's the number one cause of fly aways. People don't have good GPS so home point is from another flight else where and when an issue like weak signal or low battery happens the drone heads of wrong home point. Talking of batteries always start on a fully charged battery. Don't be tempted to use a 70% or less charged battery.
If the p3a has the same motors as the p3p,which I think it does then it has loads of power. They are brushless motors so unless you crash or tip and lock the blades while the motors are still screaming to turn they will last a long long time. Longer than the rest of the drone ;)

Bhujang Posted at 2016-4-12 17:26
All good advise so far. Especially keeping in line of sight. Never loose orientation either and alwa ...

"People don't have good GPS so home point is from another flight else where and when an issue like weak signal or low battery happens the drone heads of wrong home point. "
If you wait for the green GPS safe to fly, this will never happen.  

Thanks for all

labroides@yahoo Posted at 2016-4-12 10:09
"People don't have good GPS so home point is from another flight else where and when an issue like ...

Yes but people don't ;) then they say their drone flew away and didn't RTH lol