Landy,

There are 2 ways to appraoch this, and they can be done separatley or both together.

The first thing you want to look at is using the "Mix Shape Control". This will allow you to Keystone each of your three Output Mixes separately directly via DMX. It only takes up 8 channels of DMX per Mix, and is patched in the Cat server the same way a layer is.

This looks like it will solve your problems in pictures 2 and 3.

In picture 1 if you need say 1 layer per set piece, then you will need to either keystone on the layers or do some serious prep of your content.

To Keystone on a layer you must select the proper Visual FX mode of "Movie on Keystone" to get the Keystone parameters to work on that layer.....and yes this Effect will change your scale.

Another thing that might help you is to use Scale to shrink your layer down some. Then use X and Y position to move it to where you need it. Followed by fine tuning with the layer Keystone.

So in short for you picture #1:
1 - Set your Mix Shape Control to line up the edges as best possible for all the set pieces covered by each mix
2 - Set Visual FX to "Movie on Keystone" for all the layers you need to use

Then layer by layer:
3 - Scale image down
4 - Move with X and Y Pos
5 - Adjust with Scale and X/Y Pos to get as close as possible
(You also may want to try adjusting either the Horizontal or Vertical Aspect ratio here as well)
6 - Use Layer Keystone to clean it all up

Hope this helps