As for the standpoint on feet pointed outwards, I have the build issue. My toes naturally pointed outward. I had to literally force my bone structure to twist. What I did was tie twine from my stirrups to the girth. It forces your toes in. Ride like that for a while, and when you stand around, try to stand with your toes pointed slightly inward. Your ankles and knees will actually HURT, but it will fix the problem. It did for me!
Writing this, and thinking of the people who say Equestrianism isn't a sport ... Football players don't CHANGE THEIR BONE STRUCTURE to play better, now do they!?