its hard to believe, but there IS such a thing as too much speed. If you are bouncing someone, you need an ideal amount of e, which is about 1.5x what the other guy has, depending on the planes involved. Now, anyone who is not afk SHOULD break when you approach, ideally toward you. Or, some slicker guys barrel roll to force you to overshoot and then take a shot at you. At this point, you have to decide what type of fight to make this -- either you set up for acm, or extend to regain alt to make another run. If you decied to take the guy out now acm is needed. This is where speed is critical, if you are at 500 kts, you CANT set him up, you need to be faster than him but still in control. You zoom up above him, if he follows, you let him stall and roll down, take him out, if he doesn't follow, try another pass. Now, this is all easier said than done, and there are hundreds of variables. We have not even touched on how many other enemy are around and what threat they are to you. So, for your situation, when you are diving in, ease throttle, and as straffo said, u can put rudder over hard to burn speed, or circle over your victim while speed gets managable. D500 is not a bad max shooting range, some prefer less while others prefer more. I try to hold fire until around 400, convergence around 300-350 depending on my mood.
Now, when the nmy points up on you for a head on, you don't have to play! when you get in around 1k, do a fairly gentle maneuver like roll with a bit of rudder, or nose your plane down, just enough to screw up his shot but not so hard that you maneuver violently. The other guy only gets you when you let him. You gain nothing when you let a lower energy plane take a clean shot at you!
later