You can transfer funds to and from a brokerage account to a bank account; either a National Bank account or a bank account from another financial institution that is linked to your brokerage account.
You can transfer funds from one brokerage account to another.
You can also contribute to a TFSA, RRSP or RESP from a non-registered brokerage account (Cash/Margin) or from an account with National Bank or another financial institution.