Michael, it is interesting that I too walk with my feet straight so nobody suspected significant femoral retroversion.  As it turns out my sockets are anteverted and I guess I found a way to compensate in gait… but I have always had large ROM in external rotation (i.e.: can sit lotus no problem – even stand on head and get into that posture).  The one thing that did occur though was my most retroverted leg developed a pronation on that foot.  K-Star would say that’s a compensatory issue too — so instead of walking duck footed I medially rotate at the ankle.  I do agree with you that gradual and consistent strengthening of the internal rotators is probably the way to go.  Even if they are activated in an isometric way I think that will go a long way toward balancing us out so the deep laterals don’t always have the upper-hand!