Part of it seems to be (still) personnel related. Skinner is simply not a good PP player. He's a chaos agent at 5-on-5 but in set piece puck moving, he continues to struggle.
One thing that has gone away that was really, really delicious for them at the start of last year and in Tuch's first games with them was how he cut through the zone off-puck as a short rush option going to the net. The puck would cycle back to the left point area and he would too, then presenting a forehand option going back to the net as the puck moved back into the zone. That gives the point man on that side or Thompson on the half-wall a target, while introducing movement and decisions for the defenders that can lead to mismatches and mistakes on their part. That? It's gone. He stands around now, slightly off crease mostly, without moving to open space or cutting through coverage.
So we have Tuch stationary, Skinner having issues with moving the puck promptly or accurately, and that leaves Dahlin, Thompson and Cozens to play catch until one of them shoots the puck.
I was hoping for more bumper play since a couple teams do it so well (Boston and Tampa in particular) to create the little triangle 2-on-1's low near the net and we saw Benson creating out of that spot in preseason. But it just hasn't been there in the regular season and I don't think it will be with the five who are currently PP1. IMNSHO, swapping Skinner off PP1 for Mittelstadt might work to create better puck movement. Savoie or Benson might give them a better slot shot or shot/pass option as well, but that's putting a lot of pressure on a kid.
As for unit 2... move the puck to open man and don't dust things off for f***'s sake. People at this level don't just open up because a player is doing a stickhandling drill while standing still.