Except as otherwise provided, the elected body hereby established shall have all the powers and discharge all the duties conferred or imposed upon city councils in convention, city councils voting concurrently, or boards of mayor and aldermen acting separately, by N.H. Rev. Stat. Chapter 44 through N.H. Rev. Stat. Chapter 48 or other general law now in force or later enacted, or upon the existing city councils or board of mayor and aldermen of the city by special laws not hereby repealed. The elected body shall have the powers of selectmen of towns so far as consistent with this charter. All provisions of such laws pertaining to the powers or duties of any or all such bodies shall be construed to apply to the elected body unless there is a contrary intent or provision, it being the purpose of this chapter to confer upon the elected body all functions of the existing board of aldermen or city council, whether legislative, executive or judicial.