The director of finance shall have power and shall be required to:
(1) Prescribe the forms of receipts, vouchers, bills, or claims to be used by all the offices, departments, boards, 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 monies 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, board, or agency of the city government apart from or subsidiary to the accounts kept in his or her office.