Your fore and aft secondary's look a bit silly. What you really want is for them to be on the deck, in between the primaries.
That pic is somewhat better otherwise though.
Try moving the aft turrets further aft, shifting the stack back with them, and plopping the mast in between the stack and the bridge. It breaks up your lines a bit.
The problem with the casemates is they are still going to interfere with each other. Ships with double decked casemates, where the upper ones were directly above the lower ones had real trouble with ammo stowage and such. Check out the Omaha class cruiser
http://en.wikipedia.org/wiki/Omaha_class_cruiser
It had real trouble with its double decked guns, and those were off set a bit. I believe they eventually removed lots of them...