(d) Any authority may enter into any deeds of trust, indentures, mortgages, or other agreements, with any bank or trust company, including any Federal agency, as security for such bonds, and may assign and pledge the assets or all or any of the revenues or receipts of the authority thereunder. Such deed of trust, indenture, mortgage or other agreement, may contain such provisions as may be customary in such instruments, or as the authority may authorize, including (but without limitation) provisions as to (i) the acquisition of any project and the duties of the authority and the project applicant or project user with reference thereto; (ii) the application of funds and the safeguarding of funds on hand or on deposit; and (iii) the rights and remedies of the trustee and the holders of the bonds, (which may include restrictions upon the individual right of action or such bondholders); and (iv) the terms and provisions of the bonds or the resolutions authorizing the issuance of the same. No bonds shall be issued and sold until the secretary shall have first determined, based on the application material submitted, that the project and the financing thereof are in apparent conformity with this act and any regulations, statements of policy, guidelines or rulings promulgated pursuant to this act. If the project and financing thereof are found to be in conformity with this act and any regulations, statements of policy, guidelines and rulings promulgated thereunder, then the secretary shall, within twenty days after receipt thereof, approve the same and certify his approval to the authority. The decision of the secretary shall be final.