I had the opportunity to play La Purisima last Thursday and Saturday, as well as Olivas on Sunday. Both courses are in excellent shape (Olivas is incredibly well-conditioned given the volume of play it receives.) I also usually visit them in late December when they tend to be in excellent shape as well. If you'd like a scouting report around that time- feel free to let me know.
Quick note related to courses not on your list. Rancho San Marcos has been pummeled by the water issues we have been experiencing and in its present condition, would be a clear and dramatic second to any course on your list. Additionally, your list doesn't contain the Alisal Ranch course. I haven't had the opportunity to play that course but I've never met anyone who was disappointed with it. The Alisal River course, however, is not nearly as well regarded. Nice little resort there too if that has any value to you.
Ignoring all non-golf factors- and with your love of quirk- I would highly recommend La Purisima. I think it's head and shoulders above the other courses despite your list being full of really good courses (Olivas is on my short list of best California publics.) If we knew each other better, I would rather say terrible things about those dearest to you than let you make that trip without stopping at LP.
It's a wonderful spot.
For the after golf, Sandpiper and then an evening in Santa Barbara is pretty tough to beat. Olivas will leave you in Ventura, which you can definitely enjoy for an evening or two as well. It's also freeway close, and reasonably close to Rustic. Ojai is a great resort, and a neat little town, but a bit out of the way and can get a touch cold for golf in the Winter time. Soule leaves you in the city of Ojai as well.
LP is right next to Lompoc which is not exactly a tourist mecca. There are a couple of decent dining spots in town, but you won't regret it if you never stay there. If you do play LP- and want to stay someplace close by with a bit more charm- Solvang is just a few minutes from there and is a really neat place to spend an evening or two as well.
Frankly, you can't really go wrong at any of the five you mentioned. All of them definitely merit a visit and would be superior to a second round at Rustic IMO.