(a) This chapter shall not permit the amending of a municipal charter so as to:
(1) Permit the changing of any term of any elected official until the incumbent has completed the term to which the incumbent was elected;
(2) Permit any charter amendment in contravention of any general statute of this State;
(3) Change the qualifications of those entitled to vote at municipal elections;
(4) Change the date for holding of municipal elections;
(5) Enlarge or otherwise alter the power or procedure whereby a municipal corporation may enlarge its boundaries;
(6) Prohibit, restrict or license ownership, transfer, possession or transportation of firearms or components of firearms or ammunition, except that the discharge of a firearm may be regulated; provided that any regulation or ordinance incorporates the justification defenses as found in Title 11. Nothing contained herein shall be construed to invalidate existing municipal ordinances.
(b) No municipal corporation charter which permits nonresident persons to vote in any municipal election or to hold any municipal office shall be amended, pursuant to this chapter, so as to eliminate or limit the right of nonresident persons to vote or hold office, nor shall the percentage of nonresident officials allowed or required be changed.
(c) No municipal corporation charter which provides a method of appeal to the Superior Court for any matter shall be amended, pursuant to this chapter, so as to eliminate or restrict any such appeal.