I would advise PCH until you get to San Lois Obispo then hop onto the 101 (through Hollywood) to the 710 that ends in Long Beach to PCH that intersects with the 5 which will take you all the way down to San Diego. You'll still get much of the coast as well as other nice areas inland and it gives you much more time to spare as it cuts down on the portions of PCH that goes through places like Oxnard. Doing this will also take you through Hollywood which is something you mentioned you would like to do anyway. Happy driving!