For Sugar Run, I approached Big Horse Gap from the South and then drove out the North along 663, with the entire length of the road being doable in a sedan. Hopping up the summit road lands you in a radio station with no views, but it is an easy ascent
For Bald Knob, I headed up through the summit road from Mountain Lake, which is pretty overdeveloped but which did have flush toilets. Bald Knob would have a good view if it wasn't for the incessant rain, but whatevs
I drove along 613 from Mountain Lake toward the AT pulloff. The walk up was pretty straightforward, and the road leading up to it was doable in a sedan
Poor Mountain you can drive all the way to the summit gate about a quarter mile from the summit, with the entire length of road being doable in a sedan