I wouldn't let a little gravel scare you aware. just be easy on the throttle and VERY easy on the brakes, and no attempts at quick direction changes. The gravel sections are usually quite short
Hwy 1 is just to nice to pass up on.
As for 405s - yes - due to longer carpool lanes on than on I-5
From Thousand Oaks, if you have time, I'd head due south into the Malibu mountains, the hit PCH (Pacific Coast Hwy) run down to you hit the santa monica freeway, then head over to the 405 (check out Rock House while in the mountain, beware of squidly types going way to fast)
In San Diego county, if you have time, take 76west from I-15 and go up Palomar Mtn. my favorite route is to go up the south grade, down the east grade, 76east to 79north, head out towards Borrego Springs (CO Hwy 2), then stay to the right to stay on S2, then head west on 78 up to Julian. If you have time, then 79 south to Sunrise Hwy. If time constrained, take 8 west back home, or continue south to Campo Rd/ Hwy 94 west back to San Diego. There are lots of fun side roads, but for an intro that is a nice ride
Have fine while you are down here. My parents are in town fo rthe long weekend, otherwise I'd offer to take you out for a ride. Feel free to PM for San Diego and other nearby area riding suggestions