Rock work looks interesting and I think it will give you a lot of options for placement of coral down the road when you decide to go reef. 1 thing I would recommend, and it is totally up to you: The arrangement looks very symmetrical. Often the aquascapes that are most pleasing to the eye are not symmetrical at all and look more random and natural. It can take a lot of planning and work to make it look random
. However, it all comes down to personal preference and if you like it that is what is important.