Anyone who tried to voice an independent or exploratory thought in recent threads was fiercely pounced upon with adamant corrections and quite a bit of a bashing for their creative thinking, so perhaps all the careful toes you see timidly testing Rick's waters here are a direct result of such unfortunate treatment.
But hey, I'll bite. I have quite a nice collection of accumulated slings
I don't buy into the common picture of Counter Development
as specified in so many current texts and have my own Theory of Counter that might well get me stoned if explored here. Still, a part of my own theory supports where I think you're going with your posed question(s) above.
'Steering' (strictly in the sense of Femur Rotation) is highly useful to a degree but has a range limit
that blocks its effectiveness beyond a certain point in any well-completed turn. For me this range is even less than for most people because my own femurs rotate 'inward' a very limited amount, though they rotate outward quite a bit more than normal.
Due to this inherent limitation I've always had to implement some degree of pelvic rotation
to augment my femur rotation late in any well-completed turn. As I implement the later part of a turn my Hip Rotation combines with Pelvic Rotation to steer the skis into turn finish once the skis have turned beyond a comfortable degree of femur rotation. I further believe there are structural reasons
to begin Pelvic Rotation well before comfortable femur rotational limits are reached (and I think those ideas are well documented in your own Waiststeering descriptions).
Another element to consider is that we cannot twist both femurs beyond a certain point without our legs binding up against each other. To keep some space between the legs our pelvis must rotate
when the turn goes beyond a certain degree of completion.
Now, assuming we accept that our pelvis might rotate late in a turn to assist femur rotational range we may get into a fuzzy area trying to answer Rick's question... If we 'steer' with femurs up to a given point but then choose to (or must) rotate our pelvis - are we now 'steering' with our pelvis or are we still 'steering' with our femurs below a re-positioning pelvis? I think it depends on how we choose to look at it.
As I see it (in an Open Parallel turn) even when my pelvis rotates to accommodate bio-mechanical imperatives I'm still 'steering' primarily with my femurs as well as with lower legs/feet for precision tuning of the turn. The act of rotating my pelvis merely facilitates
a greater range of ski rotation available in relation to this Open Parallel turn.
Can I also 'steer' with my pelvis? I think I can do this also - if I sort of 'lock' my femurs in a given position and control the turning skis with waist muscles driving the operation. Not really necessary in Open Parallel since this turn is not generally used in tough-turning conditions. When using Dynamic Parallel
turns I can more usefully implement this idea as my waist muscles are quite strong - much stronger than the muscles rotating my femurs. When I need the skis to turn
despite thick, heavy snow or problematic terrain I implement exactly this idea - and it works great even with what others often describe as 'edge-locked' skis. Am I now 'steering' with my pelvis? I'd say I am.
Note that this doesn't involve 'throwing' my upper body Mass around to accomplish the technique although I think that Mass is certainly a stabilizing part of it.
Dunno Rick, was this anywhere close to where you were going?