money in a bank account, when u put money into an account it is called a deposit.

If it's your account, you go in and ask them to give you your money.

If it's not, then you don't get money from that account.

It IS their account. The only way to keep the money in an account is to sign up with them for an account that requires both signatures for withdrawal. Otherwise, the money will be used.

No, you will not lose your account money. The money you register is related to the account, not the actual iTunes software.

Generally yes but remember that you are putting the money into THEIR account and they can spend the money that you deposited for any reason and you have no recourse because it is THEIR money.