Gregory, I'm in SoCal too and have done alot of remodeling and landscaping. I'm going to give you my two cents, which I understand won't exactly answer your question, so I apologize in advance. If I were in your shoes with that incredible spacious backyard space, I'd first plant a privacy hedge all around the yard, probably podocarpus as they are very trainable and fast growing. It would unify the yard and provide a degree of shade for the existing fruit trees you love. Then, I'd get a plan together for the patio space. You have so much potential for an awesome outdoor space! Once that was done, I'd consider additional plantings to beautify the area surrounding the patio. I would not, at this point, put a large tree in the spot you have identified. My guess is that you are going to transform the yard over the years, and a tree in the middle might not be what you ultimately want. But, if you did really want a tree there, I'd go with an avocado tree (if you can deal with rodents) or a chinese elm, as they can be threaded to be lacey and not too heavy. Wishing you well!!

Try posting this on the garden forum, where you'll likely get better and more responses. But in terms of a smaller tree, you can try a dwarf lemon, dwarf lime, or guava which would grow quickly. You might also appreciate a crepe myrtle for year year color and interest. I think you should get a full landscaping plan of both your hardscape and planting areas. Some nurseries will provide this for a small fee which you can apply toward your purchases. Or pay a landscape desinger to come up with a plan that you can implement on your own. Even if you don't complete everything now, having a plan to know where you want things will prevent planting in the wrong areas now.

Thank you Design Doula,

I like the Podocarpus for an area that has been tricky for me, so I'll try it there - this side fence area - https://www.instagram.com/p/B9Nsd4fgWXY/ - I didn't want to put up a wood fence there, and my pooch loves that spot for doing his watch-dogging duties to see what's going on. And the lilac bush died, or rather I killed it I guess.

I think a Podocarpus might make for a good way to go about things there, and just trim the underside so the pooch can still see out well as well.

I'm in 10a, so it might be on the border, but I'm surrounded by 9b.

But I could see it doing good things there if it likes it there.

The patio space - I had a plan for the whole back area, but it's already changed so much.

I'd like a backyard kitchen, because inside kitchen is so small. But I'd actually like to design that patio more around the plants, rather than the other way around.

Re: a tree in the middle might not be what you ultimately want - that's something I'm trying to understand better... The tree on the left in the first picture is an avocado tree, but the heat gets to it in the summer. And I don't want it to get too far beyond maybe 8-9' high.

Veggies in the raised beds, and I want a few more of those, but I need to use shade cloth because they also get burnt in the summer.

So it feels like I need a layer higher in a tree that will help protect these things from direct sun in the summer.