If a town becomes a city under this chapter, then:
1. Its charter, if it has one, shall remain in full force and effect insofar as its provisions do not conflict with this chapter;
2. Its ordinances shall be the ordinances of the city, insofar as they are applicable, until they are repealed by the city;
3. The officers of the town shall be the officers of the city until their successors are elected or appointed and qualify, except as provided in this chapter, and shall discharge the duties and be subject to the penalties imposed by such charter and ordinances and by general law; and
4. Provisions of the town charter in conflict with this title or other provisions of general law shall be repealed thereby.