I have a 180g, and started off with a TON of rock similar to you. Over time I have pulled out nearly half of it. It's not a good idea to stack so many rocks on top of each other, as there will be no flow and a big build up of detritus. Also make sure to keep the rocks off the back wall, again it will build up detritus. My aquascaping skills suck, and I'm not happy with it even now. On my next build, I will be ordering all man made structures and just keep a section in my sump for some LR. I am not one to give aquascaping ideas, but just make sure there is an area between each rock for some flow. The first pic u posted with the rocks on the carpet, looks way to tightly packed. U may want to look into some epoxy to hold the structure together so in the future it doesn't ever fall. My biggest regret on my tank is not taking my time and doing the aquascaping the right way. Try doing some more research on different aquascapes to help inspire u.
Good luck
Sent from my iPhone