Kramer, I think that your chances of making a go of the life you seem to want to lead would be better if you included the possibility of either bartering/trading with other people for some of the things you want or need, or working as a cooperative or in a commune setting.
The problem with trying to go it alone, as you seem to want to, is that any set-back could knock you and your family out. Adverse weather-- too wet or dry, too cold or hot-- could greatly reduce the yield of one or more of your crops, and then you're in trouble. Insect pests, fungus, or even wild animals like deer getting into your garden could have serious affects.
Half an acre just isn't going to give you the reserve that you probably would need. Aside from that, it won't give you anywhere near the variety of foodstuffs that you'd need to stay mentally happy. Rabbit, rabbit, rabbit. Even if it's lean and healthy, how many times a year can you eat it without getting tired of it? And potatoes as a carb source would also get a little old after awhile, particularly to anyone who has grown up with bread and pasta and rice.
If I were trying to do what you are doing, I would want to include a few other meat animals in the mix: at least chickens or some other poultry (also a source of eggs). Coturnix quail http://www.gamebird.com/coturnixquail.html are a good alternative to chickens, and have the advantage that there is usually a pretty good niche market for the eggs. There are also pigeons and guinea fowl or other poultry you might consider.
Goats are a good source of meat and milk and cheese, and don't require a lot of space or a lot of forage compared to a cow. Sheep likewise can be kept for meat and milk and produce fiber, as well.
You don't mention tree crops, but that's a natural out in SoCal as well-- depending on the location of your acreage, you have anything from citrus to plums or peaches or nuts that you could grow for yourself and the market.
I really think you need to give more consideration to trading some of your produce or products with other producers, or marketing it in a way that brings in cash. And be realistic about how long you could live just on the things you grow yourself without going wanting some additional variety. "Back to the land" is a nice way of thinking of things, but the ideal is usually a lot different from the reality.