Regarding your answer to second question. I was not saying i am using brain wallet. Please read again.
I fully understood you.
There's a chance for that. This is what i meant to ask.
There's a chance of that, but that's almost impossible.
If you know that that any bitcoin address can be generated by 2^96 private keys on average, you may worry even more. But as I said in my previous post, a bitcoin private key provides enough security and there's nothing to worry about.