Niton
Changing my tack a little working on one area at a time trying to get the perfect view working with what materials you have.
There are several changes here for you to think about and, what not keep trying to do.
Most new Aquascapers always try to keep every thing even to get that picture perfect look, wrong thing nature every thing is not planned for that perfect well balanced look.
I have removed and moved rocks to give you the open space and the natural look.
The white areas are where the stones were.
LH end marked in red requires a rock half its size, reason the perfect curve is there.
My suggestion now is get the front finished first and completely forget about the remainder of the Aquascape then post one front photo of it please.
Finally now you can see the benefit of the Mock Tank, the more time you spend getting it to perfection the far better your Aquascape will be.
Keith