Can a bank talk or gain info about my accout with another person not linked to the account. 9

Under some circumstances, yes. First, the account agreement you signed when you opened your account gives the bank express rights to discuss the account with certain designated third parties. Second, the bank has the right to discuss its relationship with you in order to protect itself against certain kinds of losses, including fraud. As a general matter, the bank may not disclose information about your account to third parties, but it may ask questions about you.