I live at the south end of the good part of Hwy 1 (it is technically the PCH only south of the Santa Barbara/Ventura county line.)
I have to agree, except for the section from Morro Bay to Big Sur/Carmel 1 and 101 north of SF are both great. Well, 1 is great, 101 is good and takes you through the avenue of the giants. Plan on pulling off somewhere and laying on your back a few feet from the road. The trees seem like they go forever. It would be a shame to miss the Big Sur part of 1.
Do you really need to be in Santa Monica? If not cross the desert from Barstow to Bakersfield, Take water. From BFL take 166 to 101 to 1 to SF then 101 to the Eureka area then turn south on 1 back to SF. I wouldn't want to do Fort Bragg to SF in one day, not that you couldn't but you need to plan some "smell the flower " stops. You are in California after all. Not much gas from San Simeon to Carmel, one place and it is about double the normal California price.
I suggest going north on 101 then south on 1, that way the coast is on your side of the road and you won't have to fight a line of RV's to get to stopping points. Make your way back through Yosemite to 395 then home from Lancaster or north and east through central Nevada.
If you can avoid weekends do it, there are plenty of RV's with Arizona and BC license plates going 23 MPH and few places to safely pass. Not much snow this winter, I think the Sierra Nevada passes will all be open by early June, unfortunately that means a bad fire year. You may have to change your route on short notice. Pretty much any of the highways across the Coast and Sierra Nevada ranges are going to beat the hell out of anything Kansas has to offer.
Time permitting: San Luis Obispo is a nice college town with plenty of restaurants and coeds, it is also home to my mortgage.
.Carmel, Eureka, and Fort Bragg are all worth a few hours as well. If you have time the Monterey Bay aquarium is good and a nice break from the saddle. Any of the coastal towns with a harbor usually have good food and tourist trap stores. Buy a t-shirt or two. We need the sales tax revenues