Scott, thanks. It just occured to me from something you said before, that I have a very important tip for you.
It is much easier if you do this backwards. That is: Start Scene 1 with the entire model completed and showing. Think through wich pieces are going be "built" before the viewers eyes and make groups or components of each of those. Be careful not to nest things inside one another if the inside component appears after the outside one ( obvious I know but hard to keep track of when you formulating this ahead of time.) So you may end up grouping this in ways that are not the most effiicient for modelling purposes. Once you have all the pieces that you are going to have built before your eyes, go ahead, still in the first scene, to place every single section cut that you will need. So place the one at end that will hide the group when it is active and also place the one that will show the item when it is active. In every single group, make the plane that shows the item to be the active plane ( remember you are doing this backwards so this would be the last step where everything is visible) Once you have all the planes set in all the groups, create your scene tab. Now add a scene. Now edit your group that will have the last item to be built and change the active slice so that it causes the item to disappear and update the scene. Add scene, edit the next group or component that would be the second last to be built and change the active slice again to one that would hide the geometry)and update the scene. Add a scene etc. Do this all the way to the end till the very last scene has the very last group or component disappear.
I'm sure you have guessed why this is a good way to do this. If you start in the opposite direction building one group at a time and placing section slices as you build, every time you add a new scene and add section slices to that one, you will need to go back to all of your previous scenes and hide the newly placed sections that will appear in those and update each of the scenes. Much easier to start backwards and change one section at a time as you add the scenes. Each previous scene will already have it right. NOW, move all the scene tabs so that the first one is the last, and the second one is the second last etc. Now it will start from nothing and build itself.