My wife and I have driven thousands of miles in the Appalachian Mountains, the Rockies, the Sierras, etc. We generally take secondary roads. We've been on plenty of roads that were described as 'scary' and/or dangerous -- sheer drops, no guardrails -- "not suitable for RVs."
None of them bothered me -- except US 550 south of Ouray:
* Narrow (sub-standard) lanes
* A jagged rock wall on one side, and drops of up to 2,000 feet on the other
* No guardrails
* Little to no shoulder in many places
* In some sections the pavement had been undermined and there was no white line left!
Combine all that with straight trucks and semis coming the other direction, their sideview mirrors coming within inches of yours -- forcing you toward the edge. Had we been going the other direction (next to the wall) my opinion would be slightly different.
That is the one road (out of hundreds of mountain roads) we will never travel again -- not that section anyway. It is insane.
Needless to say, it CAN be done. There is plenty of traffic on it every day. It's more a matter of 'do you really want to?'
It has little to do with "skill". A blowout, an oncoming truck crossing the line, and you could easily go over the edge. There's almost zero chance of surviving that.
There are many articles and YouTube videos about US 550. Here's one I just came across:
"The Most Dangerous Road in America - The Million Dollar Highway":
https://youtu.be/gd5SYDzXKKY