The term of the member composing Class I shall correspond to his official tenure. The terms of the members composing Class II and Class III shall be for one year or terminate at the completion of their respective terms of office, whichever occurs first. The term of a Class IV member who is also a member of the Environmental Commission shall be for three years or terminate at the completion of his term of office as a member of the Environmental Commission, whichever occurs first. The terms of all Class IV members first appointed under the Act shall be so determined that to the greatest practicable extent the expiration of such terms shall be distributed evenly over the first four years after their appointment; provided that the initial Class IV term of no member shall exceed four years. Thereafter, the Class IV term of each such member shall be four years. If a vacancy in any class shall occur otherwise than by expiration of the Planning Board Term, it shall be filled by appointment, as above provided, for the unexpired term. No member of the Planning Board shall be permitted to act on any matter in which he has, either directly or indirectly, any personal or financial interest. Any member other than a Class I member, after a public hearing if he requests one, may be removed by the Governing Body for cause.