The scape is looking good. Mine is similar, so I thought I'd post pictures in case it helps. I created a small island / pillar on my far right to house my bubble tip anemone. That was really helpful as it isolates my anemone away from all my corals. Of course, that assumes my anemone never moves, but it's been in the same spot for like a year and not moved. The middle structure is a U shape but turned sideways. I'm not sure I like that better or worse, but the openess gives more areas for the fish and flow (but I like your middle structure better I think). My purple tang pretty much has claimed the big middle area and doesn't let many fish swim through there much. besides, a lot of fish swim near the front pane because they've learned that's where feeding time is!