I like most of the rock placement except the ones mixed in the roots of the wood on the right side. I would take those out completely and put some small plants mixed in around the roots. Something small that would still allow the root to show - maybe downoi. The other rocks would look good with some higher growing carpet grass as JerSaint said. They wouldn't obscure the rocks, but perhaps accent them a little more naturally.
Small thin leaved plants along the back like Mayaca fluvatillis, Didiplis diandra, Hottonia palustris, Rotalas (wallichii would be a good choice), maybe some Erio Type 2 also. Then use some larger leaved varieties in front of those stems, but keep them trimmed a little lower. Hygrophilas, Limnophilas, Ludwigias, and some Pogostemons would help the eyes see depth in the tank.