Welcome to North Carolina
Hello Rod and Judy,
Raleigh native and resident Foy here, at your service.
I don't have much to offer in terms of the "Big Empty Hole", but do have some observations/cautions for the first and third portions of the trip.
Outer Banks- It seems that your plan is to drive down from Nag's Head to the Hatteras Inlet ferry over to Ocracoke, thence ferry back to the mainland from Ocracoke Island. Be aware that there are two ferry routes off of the island--one to Swanquarter and one to Cedar Island. Given that you're then headed towards Charleston, SC, I imagine you'll want the Cedar Island ferry as it takes you to the south shore of the Pamlico Sound, a large body of water you'd have to drive around if you went instead to Swanquarter.
Blue Ridge Parkway- I am assuming your trip is in the immediate future since it's posted in the Fall/Winter section. If correct, be advised that the entire Blue Ridge Parkway is subject to closure during winter. There is no effort to remove snow and ice from the Parkway, so large sections close from whenever snow falls until it naturally melts. Today, for example, there's been up to a foot of snow near Blowing Rock, NC, temps are around zero to 5 above, and it's likely that much of the Parkway will be closed for many days or longer. It's not uncommon for the temps to remain below freezing for weeks on end at Parkway elevations. Although it appears to be a continuation of the Parkway, the Skyline Drive is a separate entity from the Parkway and it runs through Shenandoah NP. It's worth checking ahead as to winter closures for the Skyline Drive and the Shen NP. Ditto checking for closures at the Great Smoky Mountains NP. I believe the "Tail of the Dragon" is US 129 as opposed to a designated noncommercial parkway route, so there should be no lengthy closures on that route, but it's worth checking ahead for that drive, too. Such info may affect your planning.
One other note about the Parkway + Skyline Drive: Although very scenic, this is around 500 miles of 35 to 45 mph speed limits, vigorously enforced by Federal Park Rangers. If one were average 30 mph with stops included, that would be about as quickly as you could figure on making that trip. That means two fairly long days in the saddle, at least. But, from where the Parkway ends and Skyline Drive begins (at I-64 just west of Charlottesville, VA) you can get off to either the Valley side or the Piedmont side and be but a short drive from all sorts of Civil War sites, so going all the way to the north end of Skyline Drive may not be necessary, unless you're headed for DC, anyway.
Enjoy!
Foy