A few things from BF'42 vet..
All I can say is that when you find a pilot superior to your skills, fly against him until you learn how to down him. All pilots have a weakness. Sometimes even the best miss the sight of enemy, don't bother with their rear (some Stuka there, bwahah..) or are just too concentrated on the task at hand.
I can't say anything for the JoyToKey software, I have never needed it since I started flying on BF '42. I have a.. how would i describe it.. a sixth sense and years of experience about what the pilot in my sights or on my six is going to do.
Also, the view behind you is the most useful and will often tell what enemy is pulling out of his sleeve next. I rarely go down (unless on field rearming or repairing.. or that stupid tree/pole there) and it's pretty much because of this awareness I keep on enemy. There are hints of what's going on all the time. I keep track of the map, the kills (who killed what with what) and I link these all the time. Of course I drop most of this when target emerges.
The map tells you SO much even if nobody spots for enemy planes or other targets properly. Someone dies to a 109 strafe and disappears from the map.. I see you. Someone (in current FH2) spots a Spit without binocs, making himself blink yellow on the map (this could be a bug, but I rarely see the actual target
).. I see you. There's a huge load of kills for Hurricane and only one flag where fighting is going on.. I see you. The information is there.
When someone gets on your tail without you noticing it, you still have a chance. More than often (happens to all) the guy on your tail shoots just a bit too soon and you can see tracers go by. Time for a half barrel roll with a dive against enemy. Or fake split-S followed by real split-S. A thousand choices and almost all of them can and will save you. Just don't pull straight up or keep going around :p A good pilot will shoot you if you go straight up or take some distance and boom 'n zoom you while you turn and burn.. You will soon learn to keep correct height for these manoeuvres.
Only thing that really makes me sad is that DICE left out the gravity on BF2.. BF'42 is just SO much more fun when going against good pilot and that's why flying is fun. In FH2 I sometimes get dissed by other players when I don't use 109 to strafe something for kills, but entertain the 2-3 enemy planes with it. Bleh..
Anyway, keep your head cool, lead your targets more when you think it's enough and check your six every chance you get. Also, offline training is excellent for manoeuvres and all pilots love Il-2 Sturmovik: 1946