I really like this design, although I dont have much input. It'd be great if you keep this thread updated as your project continues!
I live further north and on the coast, so I don't know exactly how well it would work for you but in some of yellow sections of the understory (in sun or shade) you could introduce a spineless variety of Prickly Pear. You can make a simple soap from the pads, eat the new tender pads like a vegetable, eat the sweet flowers & fruit raw. Also the fruit has many hard seeds which can be ground into flower. I just got a few of these and they are spreading quickly.
Also, red/Daikon radishes & carrots grow super well underneath of our pear tree, we never irrigate them and theyre the biggest radishes we have!
Cheers