In addition to the powers conferred by other provisions of this Act, an authority shall have power to borrow money or accept grants or other financial assistance from the Federal government for or in aid of any project, to procure or agree to the procurement of insurance or guarantees from the Federal government of the payment of any bonds or parts thereof issued by such Authority, including the power to pay premiums on any such insurance, to purchase, take over, lease or manage any housing facilities, project or undertaking constructed or owned by the Federal government (notwithstanding Section 10 of this Act), and to these ends, to comply with such conditions and enter into such trust indentures, leases or agreements as may be necessary, convenient or desirable. It is the purpose and intent of this Act to authorize every Authority to do any and all things necessary or desirable to secure the financial aid or cooperation of the Federal government in the purchasing, acquiring, constructing, maintaining, operating, improving, extending and repairing of housing projects, in rehabilitating existing structures for purposes of making available additional dwelling units, and in the assembly of improved and unimproved property for development or redevelopment purposes by either public or private agencies.