The route makes sense on paper, but would really like some local advice about the best route between these towns, places to see, avoid and the does and don’ts – we don’t have Bears, Wolves, Rattlesnakes and Scorpions in England.
I have ridden the SC between San Diego and Reno and also ridden down the PCH. I will say that you have chosen a very tough route and are proposing a very ambitious pace. I won't comment on whether you are biting off more than you can chew because I don't know you, but I will say that your route and pace would be too ambitious for 99% of the bike tourists I have met including myself. It would be too much mileage for most folks on the coast and a lot of your route is MUCH more difficult.
Strong winds and steep climbs are likely to be combined with extreme heat some of the way any time after all the passes are cleared of snow. We had 110F heat for some of that route and we were early enough in the season that a lot of facilities at Yosemite were not yet open after winter damage.
As far as the "Bears, Wolves, Rattlesnakes and Scorpions", beyond using good sense with regard to food storage in bear country, I wouldn't worry much about critters.
My suggestion would be to try to allow a good bit of flexibility in your time table in case you find that the pace is a bit much. 100 mile days, some of them with over 5000' of climbing are tough in any case, but throw in a howling wind and/or some 100F+ heat and you may not find your proposed pace realistic. Barring that you might leave open the option to stay on the coast more of the trip if necessary.
Another thing... I am not one to usually take days off from riding when on tour, but Yosemite is well worth taking several days or a week to see and do some hiking.