"Anonymous. It is as simple as this. Do you believe that the first step is a down step. Down is into the floor. Or do you believe it is along the floor with drive from an already lowered position."
It is not a "down step". However, if you consider that the first step begins when the moving foot passes the standing foot, then this is before the lowest point of the body's swing has been reached, so there is indeed some loss of altitude early in step one. The lowest point is going to be when your feet are furthest apart - that is simple geometry. And that point is formally contained within step 1 - though it might be more usefull to think of it as occuring between step 3 and step 1.
Further, everyone who dances that way - which with today's norms of dynamic dancing is everyone who is anyone - is going to use their knees to round out the trajectory, meaning they will be lower before and after their legs divide than they would be if they danced over straight legs. Dancers of 15 or more years ago did not did not move so much, did not drop so far into their leg division, and so did not have as much of this additional softening of the knees.
"Which brings us to commence to rise and turning at the end of the first step where swing comes into the picture after or during the second drive. Refer to Dynamic Balance in Dance Vision 4."
You will not learn the ultimate principles of dancing from a video tape. The simple reality is that the whole movement is a swing. You may prefer to think of the part after the first step as the swingiest part of the swing, since you start to feel the incline of the body there, but the whole thing, relatively flat base of the trajectory included, is swing.
As for the commencement of rise, formally that would be the foot rise that occurs as the new moving foot draws near to the standing foot at the end of step 1. Heel toe footwork means that the heel is already starting to rise by that formal end of the step. But visually, watching actual dancers, the upward trajectory begins earlier, from the moment the feet are furthest apart into step 1 - the knees soften as the body arrives over the newly placed foot, but not quite enough to keep the path level, instead there is a very slight upturn to the trajectory. (If a heel turn is to be lead, the knee is not allowed to soften so much, and that component of upward trajectory is more magnified)
As for the turn, that begins in the rotation of the body to an opposite side lead during the placement of step one. This is a change of body orientation, but not yet a turn - there is no change in trajectory across the floor. It becomes an actual turn only as the body reaches its peak of rise and begins to lower in a different direction. That is to say for figures making 3/8 turn. For the 1/4 turn figures and closed changes, the foot pressure out of step one has a sideays component that diverts the trajectory somewhat, off the inside edge of the foot.
