You have a beautiful garden and I am sorry you are having difficulty with the zucchini but I have to say the good really outweighs the bad here. Wow, it looks great. Everyone in Florida experiences insect and disease issues, it comes with the territory here. I do not think you have a calcium deficiency which would manifest itself as blossom end rot in zucchini. Flea beetles are tiny, very hard to see, and I would probably go with that diagnosis. Spinosad is an organic spray that should help. Follow the labeled directions carefully and never spray during the heat of the day.