Here are some P-38 films I posted awhile back that might help you out.
P-38 Films More P-38 Films And here's a thread about the P-38 with posts by other P-38 dweebs like OIO and myself about various maneuvers and tactics against some of the same planes you're having troubles with. In that thread I also posted a film of a duel with a Spitfire Mk XIV against me in a P-38L.
P-38 thread Try using the vertical as much as you can in the P-38, it's probably one, if not the best, vertical fighter in the game because if its excellent energy retention and its very gentle stall characteristics. You can literally keep the P-38 standing on its tail in the vertical at speeds as low as 20mph.
It also helps to know about the planes you are facing too. Get to know the various planes strengths and weaknesses and use that to your advantage. For instance, with a Spitfire keep the fight above 300mph if possible because Spitfire is a better turner at 250mph and below while the P-38 has the advantage at 300mph+. If you find yourself in a slow speed turn fight, try to force the stall fight (speeds below 150mph) because once again the P-38 has the slight advantage in stall fights do to it's better stall speed handling, gentle stall characteristics and no torque but at mid-speed ranges the Spitfire will chew you apart.
The same with the N1K2, fight them as you would a Spitfire. With the slower speed of the N1K2 (as opposed to the Spitfire MK IX), it's easier to use vertical maneuvers against them, so that's the recommended tactic but if all else fails, stall fighting is another option against the N1K2 as they too have a slight disadvantage in a stall fight against a P-38.
You'll soon find out that the La7 is one of the easiest planes to fight against and is by far not the uber plane some whine it to be. The only real advantage the La7 has over the P-38 is its speed below 16,000ft. Above that altitude the P-38 pretty much holds most of the cards against it. But you have to be aware that while the La7 might not be able to out turn a P-38, it does have a better initial turn rate for the first few turns which a lot of La7 drivers use to maneuver for the head on shot and it also has a better roll rate at high speeds but drops off at lower speeds. The best tactic against them is to get them to turn fight, as the old saying goes, out turn the planes that can out run you...
But all this stuff is will do you no good if you don't know what the P-38 can do. You have to know how to use the flaps and when to deploy them in any given situation. Throttle control is another important factor, especially in maneuvers like rolling scissors where both flaps and throttle control are important for success.
As you've found out the P-38 is a fantastic plane to fly and fight in and if flown correctly one of the most dangerous foes you can run up against. I'm sure OIO will stop by this thread and post some of his thoughts and I suggest you read his posts as well. If you ever need any help in the P-38, just holler and one of us P-38 dweebs will come running.
One other thing, head on over to
NetAces and read Rocketman's lectures on the merge and Bullethead's lectures on Energy management and tactics if you haven't done so already. You'll be surprised on how their lectures will improve your flying and fighting.
Ack-Ack