1) whats happen if tomorrow all BTC is 1$ worth?
Hooray! Then I can buy a lot of very cheap bitcoins!
2) what if all countries govoment do crypto currency eg. bitcoins illegal?
Then people will have to avoid telling their government that they are using bitcoins.
3) I can put my bitcoins in a physical product where I can graders me much better against the volatility that is bitcoin exchange rate?
I don't understand what you are asking. You can certainly exchange your bitcoin for other products if there are any you would prefer to have. I have exchanged mine for Pizza many times. Mmmmmm pizza.
4) The very best way to protect against a hacker attack or against a steal all your money from your wallet ?, are there any ways to choose a safe solution here?
Make sure you are using a truly random source for generating your private key. Do it offline, and keep it protected from access by anyone else.