For any urban renewal project initiated under this act:

  (a) Where the project was initiated prior to June 22, 1968, the local legislative body by resolution may exempt the project from the provisions of section 4, as amended, relating to district areas, citizens’ district councils and coordinating councils on community redevelopment if on that date, of the persons residing in the project area at the time of project initiation and requiring relocation, 50% of such persons had relocated in accordance with law, or if on June 22, 1968, there were fewer than 100 such persons remaining to be relocated. The provisions of this subsection do not apply to a city of over 500,000 population.

  (b) Where the number of business establishments in the project area exceeds the number of occupied dwelling units in the area, the majority of the citizens’ district council need not be composed of citizens living in the development area.

  (c) Where a citizens’ district council is established pursuant to this act, it shall serve in lieu of and shall be deemed to satisfy all requirements relating to an urban renewal neighborhood advisory council required to be appointed pursuant to section 3 of Act No. 323 of the Public Acts of 1966, being section 125.963 of the Compiled Laws of 1948.

  (d) Where a hearing is required to be held prior to the adoption of a development plan, in the case of a neighborhood development program to be carried out under applicable regulations and guidelines of the United States department of housing and urban development, notwithstanding the notice requirements of section 4, notice of the hearing shall be deemed sufficient if such notice is distributed door-to-door and mailed to known property owners only in the specific area or areas where property is to be acquired or rehabilitated and mailed to all community organizations known to be interested in the project and posted in appropriate public buildings and appropriate other places of public gathering.

  (e) The boundaries of the district area may be revised by the local legislative body if the existing citizens’ district council is notified in writing by the local legislative body at least 10 days prior to final action on the revised boundaries. If new area is included in the revised district area, persons residing in or having a demonstrable and substantial interest in the newly included area may be elected or appointed to the revised citizens’ district council in the same manner of selection as the original citizens’ district council. Notwithstanding the maximum size prescribed for citizens’ district councils, the number of persons to be selected to represent the newly included area shall be determined by the local legislative body. If the existing citizens’ district council disapproves the revised boundaries or number of persons to be elected or appointed to the revised citizens’ district council and so notifies the local legislative body in writing within the 10-day period, final action on the revised boundaries or the number of persons to be elected or appointed to the revised citizens’ district council shall not be taken by the local legislative body for at least 30 days after receipt of the disapproval notice, during which time the local legislative body shall consult with the citizens’ district council concerning its objections. Where a district area is revised persons serving on the citizens’ district council as residents of the district area who no longer reside in the revised district area shall not thereafter serve on the citizens’ district council for the revised area unless they are reappointed or reelected as persons with a demonstrable and substantial interest in the revised area.

  (f) Vacancies on the citizens’ district council may be filled by appointment of the chief executive officer of the municipality.

  (g) The time provisions of section 4 are directory and not mandatory and any development plan adopted after consultation with a citizens’ district council as provided in section 4 shall not be invalid because such time provisions were not strictly complied with.

  (h) All citizens’ district councils established as of the effective date of this section are validated notwithstanding noncompliance with the provisions of section 4 and all development plans heretofore adopted and all other actions heretofore taken by a municipality after consultation as required in section 4 with a citizens’ district council shall not be invalid for any irregularities in the establishment, appointment or selection of such citizens’ district council.