The unit owners’ association is responsible for the overall administration of the property through its duly elected board of managers. Each unit owner shall be a member of the association. The association, whether or not it is incorporated, shall have those powers and responsibilities specified in the General Not For Profit Corporation Act of 1986 that are not inconsistent with this Act or the condominium instruments, including but not limited to the power to acquire and hold title to land. Such land is not part of the common elements unless and until it has been added by an amendment of the condominium instruments, properly executed and placed of record as required by this Act. The association shall have and exercise all powers necessary or convenient to effect any or all of the purposes for which the association is organized, and to do every other act not inconsistent with law which may be appropriate to promote and attain the purposes set forth in this Act or in the condominium instruments.