Goob, glad you said, it, I was reading on and on, and no one else seemed to realize that. Twisty stick= unintentional rudder use occasionally, and I would imagine even the best pilot would experience this slightly, probably without noticing. Ya gotta figure, even the smallest amount of unintentional sideslip bleeds E and speed, which after a few turns in a fight adds up pretty quickly. Totally independent controls are definitely better.
and Rutilant... you forgot one...
Rudders are for aiming, unless you always..
C) believe that your opponent will only do what you expect him to. Slightly feathering the rudders as needed can help with the slightest gunsight correction when the other guy zigs instead of zags, etc. But I guess I'm just one of those unskilled dweebs that enemys refuse to fly straight for, and who can't make the perfect setup.

All flight controls are integral to any fight. Rudders can be invaluable as part of ACM. I don't see how the two can be separated. I would defy the best "stick" around to either lock his twisty stick axis, or keep his feet off the pedals, and see what happens to his overall success. A good pilot could compensate pretty well I'm sure, but the rudders are too useful to discount them so easily. As far as using rudders to aim meaning you have blown your setup, I suppose the alternative is to disengage and try again for the "perfect" setup? uh huh... IMO, pedals are the only way to go.
Creamo, I would second the powered USB hub suggestion. X45 and CH pedals here, never any "drop out" problems... though the pedals are older gameport ones, but the X45 is plugged in to the hub. Hope it helps.