It would be better over 3 days. As most will tell you stops in Monterray, Carmel and Big Sur are pretty well musts on the PCH and it will be 400+ miles so an early start will be needed!! It's a fabulous drive ... if I were you I wouldn't waste the opportunity
Absolutely this ... I would recommend Scoma's ... on the water, great views and grub
Make sure you drive out to Napa and do a couple of vineyards
If you're driving down PCH (1) to LA give yourself enough time to go by Carmel, and Monterray ... its a great drive
For my money just drive through...