No transfer of any function made pursuant to this chapter shall be construed to impair or alter any existing rights acquired under the provisions of chapter 35.58 RCW or any other provision of law relating to metropolitan municipal corporations, nor as impairing or altering any actions, activities, or proceedings validated thereunder, nor as impairing or altering any civil or criminal proceedings instituted thereunder, nor any rule, regulation, or order promulgated thereunder, nor any administrative action taken thereunder; and neither the assumption of control of any metropolitan municipal function by a county, nor any transfer of rights, powers, functions, and obligations as provided in this chapter, shall impair or alter the validity of any act performed by such metropolitan municipal corporation or division thereof or any officer thereof prior to the assumption of such rights, powers, functions, and obligations by any county as authorized by this chapter.