1. Now Myetherwallet was hacked by random password algorism.
2. It is possible to pass the Ledger nano's recovery sheet.
3. Hacker can buy another ledger nano wallet.
4. They can put the hacked recovery word to the new wallet.
5. Our asset is stollen easliy.
6. Paper wallet( Bitaddress ) is also same above.

Am I much strict?
I dont know how I can keep my coin perfectly safe.
I know there is no perfect about anything in the world.
But can you notice the best way to keep the coin safe? 
Or can I make the hardware wallet only for me?
I can do programming and machining material because I am a engineer.
Thank you for reading my long question.
Have a nice day