Except with reference to the Senate sitting as a Court of Impeachment and the Court on the Judiciary, general administrative authority over all courts in this State, including the temporary assignment of any judge to a court other than that for which he was selected, is hereby vested in the Supreme Court and shall be exercised by the Chief Justice in accordance with its rules. The Supreme Court shall appoint an administrative director and staff, who shall serve at its pleasure to assist the Chief Justice in his administrative duties and to assist the Court on the Judiciary.