I was living in OC for 6 years, the last 3 were spent renting in Newport Beach in the back half/guest houses of really nice people on Balboa and Lido Islands, always looking to spend my saved money on a sailboat and become a liveaboard in OC, so I've been in your boat shoes. Anyways, the liveaboard thing never materialized there.
Newport has a strict, basically impossible legal liveaboard requirement. LAB's have to stay on moorings and aren't entitled to shower facilities and parking like most dock-marinas. Additionally, the boat needs to be 100% self-sufficient with power and water. I was hopeful thinking that some of the low-key people with a house and dock in their backyard would be willing to trust me, and negotiate, just like if the boat was a guest house I could rent, but I never ever found something like that, or heard ofof anything like that. I had a job that got me introduced to a lot of people out there in the harbor too, made friends with their family members who were my age, and still, no chance. I don't think homeowners (especially in $1mill-$6+mill homes, with reputations)
would risk breaking the laws that harbor patrol has against being a liveaboard. The rules are in place to keep homeowners and safe boaters happy, and the harbor clean, etc..
It would be awesome if you found something, though, so good luck! Newport Beach is basically the perfect place to live and the harbor is always exciting. Dana Point, I believe, is not a LAB-friendly harbor.
Anyways, if you had to stay in OC I would suggest seeing if you're willing to stretch a little further up to Alamitos/long beach/san pedro. Huntington Harbor is a good community with people who have boats on their backyard docks, but barely any sailboats because of the PCH bridge seperating it from the ocean. Alamitos is really nice, for that reason they are probably not open to any more LABs then they may already have, and san pedro and wilmington and cabrillo are even farther for you. My research on the subject of liveaboards in this area, seems that currently the long beach area (Wilmington) marinas are vulnerable to losing money on empty slips and if you find a reasonable private marina, and promise to stay a long time, then maybe they set their own rules on LABs... again, this is on hear-say from forums and research, I don't know the real story.
I moved up to the South Bay, Redondo Beach, for 2 years renting a house and pursued the liveaboard goal, and finally began showing up in person, dressed nice, as much as possible to several marinas in king harbor and MDR, trying to convince them I'd be an ideal liveaboard. It finally worked out up here. The stars aligned for me for the first time in my life. It's hard though, seems word has got out in the last 10-15 years how great being a liveaboard can suite the right people who want it (especially in SoCal)... so, now there's waiting lists and all but 1 marina told me they were "already over our limit, sorry."
Size of the boat is the initial key to getting a slip, smaller slips are more often of rotating availability. Unfortunately the available slip-sizes are an indirect relationship with the size of boat you'd want to live on. Ideal LAB boat being 30ft + slips are harder to come by than 20' to 25' slips, and I learned, by visiting, that most marinas in LA required 35ft or 30ft minimums just to be considered for a LAB.
Good luck, though, Newport Beach and living at a dock with a facility and a boat to sail on, is a dream come true for a lot of people. I think that's why it's so difficult.
With all this said, I think the only way to have a chance at making it happen would be to go down there, rent a paddleboard or get on a bike and look closely at who's got rooms for rent in their house (they are willing to trust tenants, and seek rent money) and see if they have a dock or dock/un-used boat combo. Contact realtors, they are in-the-know down there, contact boat brokers, they've got some of the best experience and relationships down there. Or look at who's got For Sale signs on their boats behind their house, maybe see if you can offer renting it monthly, to live on it, keeping it clean and looking like nobody lives on it, maintaining it, staying away at work/school all day, not having parties, and maybe the owners will be willing to let that happen in order to regain a little money invested in the boat while it sits un-used or for sale.
There are a lot of un-used boats tied up down there, so if you connect with the right person, maybe it'll be right-place, right-time, right-people, and work. Chances are likely slim though.