I'll give you my honest opinion and please I do not intend to offend. If it were me and were all different in what we like. I like your tank and I only have a BC29 so I'd love to have that tank to scape.
So if it were me I'd do 2 rock scapes on each side and leave the center open. I'd make one side on the bottom a nice through cave near the sand bed. The other side I'd do a nice through cave in the middle. That's just me though. It would open the tank up and give it a nice natural look IMO
You have nice rock to work with and a beautiful canvas to start off with. One day I wish to own a bigger tank.
Either way it's a great tank and as long as you like it that's all that matters.
The beauty is in the eye of the beholder not the viewer