I think the woes come from not playing the 1-3-1 PP setup properly.
The two posters above touched on not having an extra Dman on the blueline. This is because we set up in the 1-3-1 scheme, an extremely aggressive setup; in the right hands.
1 near, or behind the net. (1)
1 near left circle/halfboards, 1 in middle of ice, 1 on right halfboards. (3)
1 at the point. (1)
One would think with our possession players, this would be an absolute lethal PP. I'm a huge fan of this setup when done correctly. Passing is a must in this system, which is why that's all our players ever seem to do. The problem is, they do it to the point where they pass up shots.
Man on the point gets the puck. Really, he has only 2 options -- left halfboards, or right halfboards. Can't really fling it to the middle guy, or the guy down low. Why? Passing and shooting lanes are likely clogged by the PK. So he passes to Right Halfboards.
Right halfboards is also limited, and likely being harassed by a PKer. How do we get lanes open? MOVE. This was the biggest problem on the PP this year, besides the lack of shots. Zero movement. When we moved on the PP, it looked deadly. This is a huge reason why it came alive in the playoffs.
So Right Halfboards man MOVES, and opens up space for himself, and draws some PKers to him. He dishes to man by the net, who dishes it in the blink of an eye to the man in the middle for a goal, or a supremely high scoring chance.
The third thing wrong with our PP. Our passes were too predictable, and slow. Zippy, aggressive passes are needed. Stun the PK. Make them unsure where to turn their heads next. That indecisiveness leading to a poke check from the PK and loss of possession? Can't have that. Don't sit there with your puck on your stick. Make something happen by either moving or passing. If passing lanes aren't open, move. If you can't move, pass to someone who is open -- there will always be someone open on a 5 on 4, eespecially if you have 2 defenders drawn to you.
tl;dr: Our PP sucked because 1.) They passed up shots, 2.) they didn't move, and 3.) they didn't pass quickly enough or aggressively enough.
1-3-1 PP is awesome when used correctly. We didn't use it correctly this season.