Having taken a 28 foot A over part of that route, as well as trucks pulling trailers, and the family cars, I would say it is a qualified yes. Much of the route has wonderful views, but it is narrow and twisty and doesn't have nearly enough pull outs. It is much more enjoyable it the MX-5 than the other vehicles:-)
We stayed at the Caspar Beach RV park near Mendocino. It was okay. We've also stayed at Bodega Bay RV Park, which was much nicer. There are other RV parks along the coast, but to my recollection, while many state parks allow RVs, none of them have any hook-ups.
I hate driving Highway 1 between Stinson Beach and Marin, in any vehicle. It has a stretch of extremely narrow road with a sheer drop off (!) and one must fend off an abundance of impatient idiot drivers. It's a white knuckler even in the MX-5. We've not driven that stretch in the RV, and if I have my way, we never will! Unfortunately, the best option for getting back to 101, Valley Ford road to 116, splits off north of Pt. Reyes and Drakes Bay. Depending on your comfort level, it may be worth back tracking to that route, because Pt. Reyes is worth a visit.
Also, for reference, Caltrans has a couple of maps available that can help you plan your route. The truck map shows where trucks are limited, and what those length limits are; and an RV/Bus map that shows where RVs and buses are limited. For example, on most of Highway 1, buses and motorhomes over 40 feet are prohibited.
http://www.dot.ca.gov/maps.html Have a great trip!
Mrs.Gryphon