TenOC, that sounds like a good route -- as I am sure you know, distances in California are longer than they appear on a map! So no matter how you sequence your destinations, there will be a lot of back and forth.
If you are heading from DV to the central coast in May, maybe stop off at the Carrizo Plain -- you can see the San Andreas fault up close (straddling it!!), and all of the stream beds are offset due to crustal movement. Plus the wildflowers are good to great (depending on how much rain we get this winter), and there is wildlife (antelopes etc.), and good boondocking and star-gazing.
You'd catch Highway 58 at Mojave and head west to Carrizo. And then 58 to the coast is not a bad road -- I have towed my trailer on it a couple of times.
Moving on to Sequoia, have you decided how much time you want to spend there? That is my favorite area of the Western Sierra -- we like it more than Yosemite. But if you are not a hiker, there is not all that much to do -- maybe three or four days' worth.
If you can live without hookups, I recommend Azalea Campground, up near Grant Grove -- it is big rig friendly. (I've forgotten what kind of a rig you now have, sorry to say.)
Also, Dorst Campground, near Lodgepole, is also ok for bigger rigs. Lodgepole Campground is less so -- the sites are smaller.
And there is good boondocking up near Big Meadows. Sometimes, the gates on the forest roads are open in May, depending on the snowpack.
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)
Our trips -- pix and textAbout our trailer"A journey of a thousand miles begins with a single list."