Apply a Levels effect after the Ball Action to make it strictly b&w. Or use the map as a property map for Particle Playground and a layer grid. Alternatively, do a stack with the Shift Channels effect or similar to create Alpha channel based on Luminance and treat the edges with Matte Choker or Minimax to get rid of the black fringes...

Mylenium

Blend modes are the key. Both in the effects and on the layers.

You're trying to do too on too few layers and you've mis diagnosed the source of your problem. 

CC Ball action is going to create a ball everywhere there is an opaque pixel. You need to create a world map that's white where the land is and transparent where the water is. If youre image is truley black and white I'd use Set Channels and simple matte Choker. Set alpha to Luminance. Another approach would be to use a copy of your Black and White world as a track matte. The key to success is to have a white only land mass that you can apply Ball action to.

Now when you apply ball action you have white balls on a transparent background. You can then animate a wipe to hide the balls so that the light beams will go away as they do in the Universal Pictures opener.

Once you've got your white balls on a transparent background nest that comp and apply CCSphere. Render only the Outside to hide the back of the world. Now animate the rotation of both the world in color and the world of white dots so they are in sync.

The next step is to pre-compose the white dot world and apply light burst. Change the blend mode of that pre-comp to ADD and you should be ready to tweak settings for the final result.

That should do it. Whenever you run into an AE problem you can't solve, back up, and try and see where the problem really lies. In your project, CC Ball action was creating balls on both the white and black portion of your image. The solution is to remove the black portion of the image.