The General Assembly, in recognition of unlawful campus and school disorders across the nation which are disruptive of the educational process, dangerous to the health and safety of persons, damaging to public and private property, and which divert the use of institutional facilities from the primary function of education, establishes by this Act criminal penalties for conduct declared in this Article to be unlawful. However, this Article does not modify or supersede any other law relating to damage to persons or property, nor does it prevent a public institution of education from establishing restrictions upon the availability or use of any building or other facility owned, operated or controlled by the institution to preserve their dedication to education, nor from establishing standards of scholastic and behavioral conduct reasonably relevant to the missions, processes and functions of the institution, nor from invoking appropriate discipline or expulsion for violations of such standards.