There are no guarantees in life and no 100%. The only thing which is for sure is, that we have to die at some time.
Emma is as idiot-proof as it can be: There are videos (for example this: https://www.youtube.com/watch?v=PKSyZ2amVNY) and tutorials around, even so it is harder to do something wrong than to do the right things.
If you want to have sailfish on your device, flash it! There is no other way. No risk no fun. What’s the point in buying a Ferrari, when you are in fear it breaks down when you drive faster than 50 km/h. Why do you leave home when you can have an accident outside? Why are you going to sleep when there is risk, that you don’t wake up the next morning?
Maybe because these risks are less probable than the fear to miss your whole life.