I dont know how to fly with F3, it just confuses me, I do like to fly around with F4 though, because I like to look at the plane im flying and admire it
as for making crazy deflection shots, I just take my speed, pull in so the plane im shooting at is in my side veiw, then roll and shoot when I think they (my cannon rounds and the plane) will cross paths, I have made some pretty unbelivable shots like this