Did that recently on a section with my 13yo son. I would rate the part from Carvers gap to Hump mountain as "moderate quot;. Especially the balds. Scenic..yes. Tough…not at all. Some short climbs but with good trail. From Overmountain to 19E we did that 10 miles in 4 hrs, keeping up with thruhikers who have been on trail for 6 wks. Hardest part is the boulder jumbles which are supposed to be the trail when coming down to 19E.
Good thing you didnt take him UP Roan from Hughes gap or 19E.
Roan is beautiful in bloom, and even more so when you get there by earning it (ie climb). Quite a lot of Rhododendron were blooming a few days ago.