I thought the skill shot was tied to the bullet targets on the left of the playfield. You want the ball to hit the bullet target that is lit. I could be totally wrong on that though.
As for the bomb targets, I made a deflector to go above the targets to prevent airballs. I think the pin came with one orignally, but most don't have it. Here is an example of what I'm talking about.
I can take a pic of mine if you need a better view.