What is sketchy?
Ask at the Nomads forum about the area you're interested in.
Yes, there are road repairs currently on Mex1 in Baja Norte, I wouldn't try to read too much into that. Few gravel sections with lane zigzagging with red traffic cones just like in the US.
There are some old sections - not repairs - with cracked pavement and poorly filled potholes where you can do 30-40, not 60. There is usually a traffic sign with lower speed limit then.
And - yes, there are hills and sharp turns. The road straddles the mountain range all the time, except for when it goes through the desert. Boredom will be a bigger enemy than the road condition.
4-lane exists only to the South of La Paz, AFAIK. Everywhere else it's 2-lane, one Northbound and one Southbound, 9-10ft wide lane at best.
People don't take RVs to Baja? How then all those rigs on campgrounds got there, I wonder. Ah, - yes - forgot about ferry from the mainland. There are two, one to La Paz and one to Santa Rosalia. Terribly, ridiculously, unbelievably expensive with RV. Besides, coming from WA, this doesn't sound convenient, and you won't see Baja then. If the goal is to get there, not to see anything, then you don't need to drive that far - there is international airport in La Paz, this will be much cheaper and less stressful.