Nice brick work. (I come from a family of stone/brick masons.) Looks like you have some masonry skills.
Wonder if you ever tried a steal/metal version..?
I have some experience in building a J. Llopis ( pronounced Yo-pee )ovens and you have given me some great ideas, an oven could be incorporated into your design very easily..
I had an in ground swimming pool once, got tired of it and converted into a pond with fish and Cherokee water lilies. worked great.
You will have to use an aerator to keep balance in a small pond. It was very enjoyable.