The terms of a trust to provide for perpetual care shall be designated in a written agreement between the registered cemeterian, permit holder, or any other person subject to the trust requirements of this subtitle and trustee. The terms of the trust agreement: shall conform to this subtitle; and may include provisions about: payment of income; accumulation of income; reinvestment of income; administration of the trust fund; and powers of the trustee as to investments. A trust agreement shall be irrevocable. However, a trust agreement may: give the registered cemeterian, permit holder, or other person subject to the trust requirements of this subtitle the right to remove the trustee and appoint another qualified trustee; and provide for the appointment of individuals as cotrustees and successor cotrustees with a corporate trustee.