What other bugs should I be encouraging and is there anything I should be doing to encourage them?
This I don't know much about, but my inclination is that worms are just spoken of the most because they are abundant in the places where the people speaking about them are. I would think that there are other organisms that do similar work, that might be just as beneficial. Those that are abundant where you live already. Leaning on those ancient traditions, where you have the opportunity to learn about them, probably is the best way to discover this. Or ancient agricultural practices in similar climates/soil regions. People did learn these lessons over thousands of years of trial and error, so it is a waste to re-invent the wheel with our "modern" world. But, certainly there are times when a little innovation works miracles. Wish I could give you more ideas, but I am still figuring my own situation out. I do have an immense respect for the people who lived off this land for centuries, if not thousands of years, though. Agriculturally, it is an immense challenge, and nearly all information about use of the rare native plants here has been lost.
There was someone else from the Keys - name I think was 'By the Sea'? - who used to post a lot to the old vegetable forum, who strikes me as someone who might have more to offer this conversation, because I think (he?) was someone who grew organically, and certainly had a few more years of experience than I do here to draw from. I remember building up mounds being in discussions, for instance. You could also try planting beds in-ground. Some of these might be ways to control specific areas of soil for temperature and other qualities that worms or other organisms might need - or perhaps without the need of them at all - to nurture specific plants that need richer conditions.
I think you yourself talked about the benefits of cacti on soil, right? So plants like that, or ice cream bean, etc. might be a good option to grow in areas where you need the soil to be broken up and improved. I know there are plenty of more examples, but I can't think of any right now. Some of this is discussed in the fruit forum, and should apply pretty well to vegetables just the same. We will keep brainstorming and see what suggestions people come up with...
There's also trucking in debris and manure, where unwanted, from local areas. For instance here, people are always wanting to get rid of seaweed, if you're willing to do the work to collect it yourself. And as I understand it, it works great on the soil as mulch, as well as buried as compost, no rinsing needed. I haven't gotten around to it yet. But that's another way to build at least a beneficial top layer, and also help keep moisture in in dry areas. You just have to be careful with random local debris, because a lot of invasives or harmful materials can often be in there that you might not want in your soil. Improving soil, especially over a large area, is a very long process. Have you looked into how Grimal Grove in the Lower Florida Keys does it? I have not had much contact with them yet, but as I understand it the guy worked much of his life to totally transfer a pretty inhospitable landscape into a tropical plant oasis. Some of the original work, and the current restoration project, will not apply to me because they have different rock underneath their island than I have on mine, and more fresh water than where I am, but they are committed to organic growing too and probably have a lot of good ideas to share. Again, what works for fruit, will often work for vegetables. Just some ideas...