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