I'm not sure that adding minerals will increase ozone absorption in water, but the case is pretty good for ozone retention in water by adding minerals. I have not made a practice of doing this but several reliable sources have said it works.
I can't see ozone interacting with calcium in any harmful way. Calcium is a pretty stable mineral so I would suspect that little or no interaction would occur. Of course, I'm no chemist, so I'm open to a change in opinion based on scientific facts. Maybe someone else out there knows better. Coral calcium, similar to Sea Salt would indeed contain all kinds of great minerals from the seawater that it was made from, so I would think that it would be a good addition to your ozonated water.