I know you asked Steve but I'll answer re scapula on deadlift:
No you don't retract them. It puts you at a disadvantage for the second part of the pull as you have to get the bar further to be locked out. You also lose power as you can't engage as much back. If I remember later I will post a video from Andy Bolton talking about this. As a world record deadlifter, he knows a thing or two about efficient and powerful technique.