"But for the life of me I cannot figure out how you can say the body, the body being that part above the hips, I think that to you is your body."
In some cases that would be true.
But it's simple enough to figure out when the discussion is over the difference between what the body does vs what the feet or legs do, that the body is everything except the feet and legs.
"With your knees bent to an angle of 45 degrees how do you get your weight over the front of your base to be the furtherest part forward without toppling over."
By keeping moving and driving towards where the next foot will land (although it is not yet there). You obviously cannot stop in this projected, which is to say off balance, position, but you do have to go through it if you wish to accomplish the character of the dances other than tango.
"By all means drive your spine which is your centre forward but it will never overtake your foot."
You are looking at it the wrong way around. It starts out ahead of the foot. The foot then catches up and overtakes it.