If this was my tree and I had it to the point of development you presently enjoy this is exactly what I would do. Understanding that I have a real personal issue with cascade design and do not see them as clearly in my mind as I would like to, I would immerse myself in every bonsai book, gallery or web site that has pictures of good cascade bonsai (which are few) and try to analyze ever aspect of them I can make myself understand. That my friend is the truth. I have found that the Cascade is the most difficult of styles to pull off well. I am not saying that your tree is bad, the health development is evidence of your great ability to work with a tree. I am just saying that it falls into the same category as most cascade attempts and if I was faced with this result I would not be happy with it----- either. You have done some good things with the tree but I think I know you, and I think you are not happy with it. It's a great start but your stuck?
As I said earlier you need to research the style, you need to get a feel for the style beyond the falling-over-the-side-branch. You need to have a thing for the way the falling branch relates to the base of the tree. You need to have a thing for the way the individual branches relate to the larger branches they emerge from. You need to understand their importance to the rest of the tree and how they relate to each other. That's the strategy, now we have to look at the tactics: How do we get there, and a grasp of what "THERE" is.? What do we do to what, and when. That is the tactical issue, the techniques and styling skills to make "THERE" happen.
For now I believe the best thing you can do is start thinning out some of the foliage and exposing the workings of the inner branches and developing foliage pads. That should keep you busy for the time being, you cannot understand the secondary branches if you do not see them.