Dr. McGill has also talked about hip architecture as it relates to the squat. In short, the structure and orientation of the acetabulum (hip socket) has been shown to vary among individuals and this means that no one squatting style is optimal for everyone. Continue to work on your mobility issues, but realize that some individuals simply need a wider stance than others. As for the pinching in your hip, this can be a symptoms of femoral acetabular impingement. I was about to write a summary of this condition, but then I remembered that Dan Pope has already done a good job of this on his blog. The link is below.