I think your aqua scaping is fine (pictures never do justice). I would suggest, however, moving the larger rock structure toward the back of the tank so that the aquascape is not all in the same plane. You have the height variance already, now establish some variance of depth.
Also, while I can't speak for coraline boosting additives, I think you might seed your tank better by getting another, small and totally coraline encrusted rock and scrape it in the tank then just add it to your rock work.
Of course, at four months, if all your levels are where they should be, it's time to add some corals. That is going to help you alot.
Please post updated pictures down the road.
Cheers,
Ben