I always maintained that your feet are there just to make sure you don't fall over: If you have to lean or bend at the waist with a move in order to keep 'close' to your partner, then you are off-balance; you should have moved your feet to maintain your center. {With the exception of 'leans' of course}
All this 'step back with the right' etc. is not strictly necissary - you
could dance rooted to the spot and lead the lady arround you. You
could do all the moving yourself and leave the lady rooted to the spot. Neither are very nice ways to dance, but can be tactics used for certain moves or to get/give a bit of a rest after a fast move{dance
} or four.