I would say see how those 4 massive raised beds perform and you may not have to add more swales. One thing you have going for you is the groundwater hydrology in the area. Those big mountains to the south of you? When it snows and rains on them, the precip percolates into the ground and ends up running under your property. If you have well established trees, they are going to be able to tap that resource. When I lived in Las Vegas, I had a mulberry tree on my property that was planted maybe 30 or 40 years before. The trunk was maybe 8"-10" in diameter. The
roots of that tree managed to find the aquifer that underlies Las Vegas, and it needed no additional watering -- even in Las Vegas!
You might want to consider a walnut or pecan tree as a shade tree for the house. Pecans develop a very deep tap root (that is why seedlings are sold in a plastic pot that is 2-3 times as tall as other trees), and they will find that water under your property. Pecans grow very well in the Pecos river valley of New Mexico, an area with a climate that is very similar to yours. They will need a regular irrigation in the summer, but as long as they have water, they will take the 108 degree summer days. If you don't know which one to choose, you can graft a walnut onto a pecan or vice versa and have a tree that gives both.
If you start things like figs and grapes and plums from dormant hardwood cuttings, I don't think they would even need the shade cloth. The only advantage of having them in a
greenhouse or special area is that they would get more of your attention and be less likely to dry out. Once you see the buds start to swell in the spring and they leaf out, you can coax them along with compost teas.
You can probably also have olive trees in your area, but since they don't go dormant, you need a different technique to start cuttings. Here is a
link that describes that. Olives are shallow rooted though, and while I have seen some nice specimens in Barstow and Las Vegas, they were on lawns with automatic sprinklers. If a place gets foreclosed and the water supply is shut off, the olives are the first trees to bite the dust. They aren't survivors like my mulberry tree was!
As far as preparing for the long, dry summer, mulch and horse manure are your best weapons. As long as you have a ready supply, you should be well prepared.