A board member or employee of the board shall not, directly or indirectly:
(a) Have any interest in the making of any investment, or in the gains or profits accruing therefrom.
(b) For himself or herself or as an agent or partner of others, borrow any funds or deposits of this system, nor use those funds or deposits in any manner except to make current and necessary payments authorized by the board.
(c) Become an indorser, surety or obligor on investments by the board.