Love following your story! The climate and culture remind me a great deal of Jamaica.
Good fences make good neighbors. I feel your pain on people tying animals in your garden! Planting sisal and keeping your unfenced borders in thickets of native thorny species until fencing can go up is an option. In Jamaica we had "candlestick" and "horse dildo" cactus that form impenetravle barriers when planted close enough. We were dry 10 months of the year however, no hail, so not sure if you have those type of prolific cacti prickly pear seems to be many places so maybe...
Someone mentioned nuts- perhaps cashew trees and almond trees could be on your future planting list?
For erosion control, maybe small strips on contour with Canna, fever grass, aloes? I find all of those also can form pretty good weed barriers on edges of beds.
You are doing amazing work, sounds very challenging, especially the cultural challenges. In Jamaica it is called "crab in a barell mentality", as you start to climb up, everyone else pulls you down. Never stop climbing, each time you climb after being pulled down, you climb a bit stronger