It looks great. But what will happen if this stick will break? Bitcoin are lost?
Is here the way to securely create segwit paper wallet?
Yes, If the device no longer works, there is no way to recover the coins (unless they presented something in V4 that I'm not aware of). I wouldn't suggest them for storing big amounts for the long term anyway.
As for creating SW paper wallets:
https://github.com/coinables/segwitaddress