Welcome to the forum. My feeling is you can go most anywhere on public highways with your setup; certainly wherever the big rigs go. If you are concerned with overhangs and hairpin turns, I believe there is a GPS system that allows you to enter your rig's length and height and it will offer alerts as to your route.
I can't say regarding your route as I am always coming from the north. I will say I have traveled 101 throughout Oregon and have never felt uncomfortable. pulling a fifth wheel on the highway. There have been comments on these forums regarding hwy 299. I've pulled a boat on that road from Redding to Weaverville and found it to be fine.
Enjoy your fifth wheel.