I agree. Beyond the necessary minimum, the main effect of better gear is making playing... let's call it: More comfortable. A 300$ HOTAS stick doesn't make your plane turn better than a cheap twisty, rudder pedals do allow for some finer control but there's still nothing you can do with a twisty and the limit is still the pilots skill and knowledge when to use rudder and when not.
In most situations, players get shot down because if some sever pilot error, either in setting up the fight, misjudging the situation or faulty application of ACM - and not because they do have twisty & standard hat views and their enemy has a full HITAS, rudder, trackIR setup.
I think you're right, although the "necessary minimum" makes a huge difference - when I started palying AW it was with a mouse and getting a joystick with a throttle and hat switch was like night and day.
Beyond that, a good monitor makes a real difference. The player who can see more has a definite advantage.
As to the original topic: I'd add two more subsets of SA and one that I don't think has been mentioned. There's knowledge of the planes and their strengths and weaknesses, this is absolutely crucial. Then there's psychology: knowing what the other guy(s) is going to do before he does (of course you also have to be prepared for the possibility that he's smarter than you think!)
The other one is self-discipline. I get killed a fair amount doing things that I know I shouldn't do, but because I'm mad or have buck fever or whatever I do them anyway and end up kicking myself back in the tower. I'm sure I'm not alone in that, given the number of people I see doing things like chasing enemies into ship ack, creeping up on buffs' six hoping to win the gun duel, getting suckered into turning with planes that are much better at it, and so forth, that everyone but the newest players knows are bad ideas.
