More on the "hairball" end of the spectrum owing to lots of exposure, and tight switchbacks but its an easy enough road to get up and down. Blindfold anyone that's afraid of heights. Seeing the carcassas of old wrecked cars whose drivers weren't paying attention among the rocks between the switchbacks adds to the experience.
I've driven it in a Subaru wagon loaded with gear so you don't need lots of clearance. As for how long a trailer you can take down it, you may want to call some of the Cat outfitters and talk to them about what can go down the road. I'm sure if they can get down there with big rigs, you can too.
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse