The Director of Finance shall have powers and shall be required to:
(1) Prescribe the forms of receipts, requisitions, vouchers, bills or claims to be used by all the offices, departments and agencies of the City government;
(2) Examine and approve all contracts, orders and other documents by which the City government incurs financial obligations having previously ascertained that moneys have been appropriated and allotted and will be available when the obligations shall become due and payable;
(3) Audit and approve before payment all bills, invoices, payrolls and other evidences of claims, demands or charges against the City government and with the advice of the City Attorney determine the regularity, legality and correctness of such claims, demands or charges;
(4) Inspect and audit any accounts or records of financial transactions which may be maintained in any office, department or agency of the City government apart from or subsidiary to the accounts kept in his office.