I recently bought some pedals. I was under the impression that it would give me much more rudder control and therefore help me out in taxiing, takeoff, and gunnery... However, I don't feel much more in control than with my twist stick, and several people have said not to use rudder to aim. Right now I only use rudder when taxiing, taking off, aiming during strafing, and keeping a twin engine stable when operating on one engine. I did all of these just fine with twist stick and pedals don't make it any easier. So when and how should I be using rudder in general flight and in combat? Is there some major benefit to rudder pedals I haven't discovered yet?
So the first thing I'd say is that when I got first got rudder pedals it took me a while to get used to them. However, once I got used to them I found them to be far superior to a twist stick. The biggest advantage for me is that it means that your rudder inputs are not coupled to your pitch/roll inputs. With a twist stick it's very hard to keep your 3 flight axes truly independent ... a bit of rudder accidentally ends up also adding unwanted pitch or roll inputs.
As for what to use the rudder for ... I'd say just keep flying with it and getting used to it, you start to find all the wonderful things you can do with rudder. Practising coordinated turns is a good start, but I'd also suggest just trying to get a feel for the plane. Watch the nose, see how it behaves: when you do a manoeuvre is the nose sliding off one way or the other? Try and keep it from flopping about at all, try to always keep it pointed exactly where you want. You also start to just feel that your turns are wrong without it, they feel off .. they're "sloshy".
I really took to just practising and enjoying flying the plane for ages. Not dogfighting, just flying and really being in total control of it, getting it to do exactly what I wanted ... and I'm still learning. I have to say that for me personally VR has also helped a lot here, you just get such a different sense of the plane in VR.
The difference with pedals is in how precise and subtle you can be with the rudder. Things requiring very gross rudder inputs you can do with a twist, but getting the plane nailed right where you want it requires pedals IMO. I found when I really got used to my pedals, I started to see so many opportunities to use the rudder. Got a horizontal turn that's started to slip a bit higher than you want, losing too much speed? Slide it back down with a touch of rudder. Plane about to stall and drop a wing? Catch it before it goes with the rudder. Adding a bit of rudder to your defensive barrels rolls can help throw the other person's aim because you're not going where you seem to be going. Can't quite pull enough lead for a kill shot, even though you've got plenty of energy? Add rudder to the turn to momentarily increase the turn rate.
When I first started flying I basically ignored the rudder: roll the plane, pull on the elevators, job done. But after getting my pedals and learning to the use them, I started to use the rudder more and more. Then I began to wonder how I ever flew without them ... I suspect the answer was "badly".