When all of these features are switched on they work together extremely well.
Giving a move order with Aggressive fire enabled will cause any units with that order to ignore the move order and bombard any enemy units within range. This will cause the movement to halt until any encountered enemies are defeated, and then the movement order will continue.
Adding a delay will keep your unit in the starting position for the length of the delay before beginning the move order. With aggressive fire enabled the delaymove will also be ignored while any enemies are within range of bombardment. Note this will not pause the countdown timer, but they will fire despite having the timer counting down.
Aggressive fire will eliminate any enemy units within range along the path even with multiple add targets programmed in.