Where do we start?
Yes, P51s are good at BnZ, so is just about anything. Sounds like you know what it is in principle so thats a start. The basic premise is you are using a massive speed difference to close on a unsuspecting target as quickly as possible and kill them either before they notice you, or have time or speed to spoil your gun shot. A pilot that has his wits about him, and keeps his crate at or need best corner speed is always going to be extremely hard to kill in a purely BnZ fashion. Its too easy to side-step a BnZ fighter which is screaming in full tilt - espc someone who is new at BnZ.
I got a suggestion to try. Learn about pursuit curves (Lead, Pure, and Lag pursuit) and use them as appropriate. Normally n00bs come screaming in using pure-pursuit and get all frustrated they are 1, seen from miles out, and 2, miss their shot as they get into gun range cause they're slightly 'out-of-plane' with the intended victim. A useful tip is to use lag pursuit when starting your run in. This has two advantages: 1, by the time your in guns range, you will have pulled into pure pursuit and you will be 100% 'in-plane' (assuming they haven't maneuvered radically yet); 2, you will dead behind them and for the most part harder to see. In fact i dive just slightly lower than them then come up to shoot. Doing this puts you out of their site, and you can tell quickly whether or not they've seen you in advance. If they do a slight roll and slip then they know your there, they're pushing you out of their blind-spot. If they dont move and keep going dead-level, they either have b@lls of steel and are trying some cunning last-second evasive, or they ain't seen ya.
So dive to a point on their extended 6 and slightly lower than them (distances may vary depending on scenario), but you want to make sure you're coming dead at them from the lower rear to maximise success chances.
But like i said, BnZ is easily defeated by all but the n00b and the blind. What you need to do is learn how to Energy Fight - LOTS more difficult! so prac your BnZ and you will start learning the groundwork for serious E fighting.
As for your second problem. Well, sounds like your making your attack runs when you know you are opening yourself up for becoming attacked yourself. Simple answer really... Attack when you know no-one else will just cherry you while your pickin someone else. Sometimes this requires patience and discipline and experience.
And finally, why aint you supposed to "pick" a target?? Says who? Pick one by all means, and plan out your attack and retreats from that. But what i suspect your getting confused with is "dont get target fixated", eg if you bounce an intended victim, and miss, and then you notice someone else who is a bigger threat, dont be afraid to switch targets. You dont have to finish everything you start in the order you started; situations change rapidly, be prepared to adjust just as quickly.
