I am currently using blockchain info
I just want to ask, is there any possibility that blockchain will cease its operation? What will happen to my btc with them?
If you have the private key you control the money. Bitcoin does not depend on blockchain.info but to control your money you need the private key.
In such situation you could upload your private key into a desktop wallet.
They have the keys too.
They might transfer your coins before you do
They
DO NOT have the unencrypted version of the private key. To spend the Bitcoins, you need a unencrypted version of the private key. In this case, blockchain.info only have a encrypted backup of your address which means they cannot spend your Bitcoin as they do not log passwords on the server.
True, the encryption and decryption are done on the client side but not the server side, so the site don't have your private keys.
But if you have leaked your wallet identifier and password (by phishing emails or by keylogger), the person having your credentials can transfer your coin.