You can rent via using your points to make a reservation in another's name more than once per use year. You cannot transfer points to another member more than once per use year. A rental where you use your points to make a reservaition in another's name is not considered a transfer of points.
DVD has a 20 reservation limit rule in that if you make 20 or more reservations in any 12 month period, you will be presumed to be engaging in improper commercial rental activity and will not allowed to make any more reservations in that period absent being able to show reservations were not rentals.