I have exactly the same problem!Is this what you're talking about?
Lots of good things going on in your swing motion. Where you specifically aiming at a target on the right side of the range on this shot?
Good posture, one thing maybe to think of, if that was a PW in the swing, you're a little ways too far away from the ball, it's making you hold your arms 'out' to reach to the ball, rather than the arms being able to hang comfortably down from your shoulders.
You seem to be striking the ball reasonably well, what happens with your right foot, there is a reason for it, really depends to what extent that may be giving you any problems with you finding target with your shots, & your overall consistency.
Looks like it's probably your hip motion at transition & down to & through impact that's causing the right foot to fire back, your left hip is still a touch in the way through impact so your right side knee, thigh & right hip struggling to get right through the shot at impact which is why your right foot kicks back.
Good drill, should you want to change, is with a short iron say 8i. Remember not to be 'reaching' out with your arms to the ball, you'll need to set-up just a tad closer so your hands can hang down from your shoulders.
Put an extra ball touching the outside of your right heel.
Then aim to make swings through the ball swinging only at 70% (this bit is important don't try to swing at full speed doing this as that won't help you) concentrate on keeping your right foot flat on the ground into & at impact then let it roll inwards towards target & then let it come up on the toes at 90º, feel your right knee moves to touch your left knee & make sure your balanced enough to be able to count to 5 holding your finish, & through doing all this your right heel shouldn't move the ball you put next to it
Here's a vid that may be of some help to you too. Pay no attention to his comment on it about the left heel coming up in the backswing as that's not relevant to you, but look at the 'roll' of the right foot, & particularly how the left hip needs to clear left to allow the right hip, thigh & leg to come through to get through the ball to a balanced finish.
[video=youtube_share;6fKHfjuQMys]
