Regrading the "foot moving outwards" - make sure your stance width is correct - try subtle adjustments - wider/narrower - I suspect you may be a little too narrow.
Other possibility are trying to keep the back leg "too straight" when in Hanmi position - let it flex a little
Jim
Thanks Jimmy, MB corrected my position in exactly this way on the night, I know this is going to take some time to get right.
and think about the feeling of pressing the outside edge of the foot down and not just the heel.
Thanks, will try this, although not tonight

, calfs and thighs a little tight now !