LF, As a civil a/c technically you are not flying under VFR at night. To comply with IFR below 3000' only the minimum height rule applies.
In class G airspace ATC will pass traffic information on other IFR flights and information such as vortex recomended spacings. It is up to you as the pilot to position yourself accordingly behind that traffic. You may be instructed to take up an orbit in the downwind leg so as to retain visual reference with the airfield.
ATC is responsible for issuing information and instructions to a/c under its control to achieve a safe, orderly and expeditious flow of air traffic and to assist pilots in preventing collisions between a/c flying in, and in the vicinity of the ATZ.