Driving hwy 200

It's been awhile (2006) but we did what you are considering: Rte. 200 down the coast all the way to Huatulco, then Juchitan to San Cristobal de Las Casas in Chiapas, then straight back to Oaxaca City, then south on a very winding, twisty mountain road back to the coast at Puerto Escondido, then back up Rte. 200 to Zihua.
All went well except for a relatively minor accident just north of PE....which was an experience in itself....and a flat tire along that twisty, narrow road down to the coast from Oaxaca City. Fixing a flat on an extremely narrow "highway" with no shoulder, was a tad terrifying.
The least enjoyable part was driving through Acapulco on the way home. (We must have taken a periferico on the way south.) Once was enough.....you couldn't pay me to drive again anywhere near Acapulco....and I learned to drive in Montreal, which should have prepared me for Acapulco.
Generally, the roads were like anywhere else in Mexico: some great, some OK and some downright awful.
Still, an experience we won't forget.

Safety and security? What can I say? Life's a risk.