Re: Posture in Iwama Aikido
I saw some pictures of myself just after my shodan test, and noticed that I had "Iwama hip" (the posture you are talking about). While I've heard some people say that there are advantages to this posture, I took measures to correct it, as it doesn't fall in line with my ideas of correct body use. Although I've noticed it still appears when I'm doing something that is particularly "Iwama style".
So from my experience, you just kind of naturally start adopting the posture, whether you like it or not. I didn't and have worked to correct it.