In all honesty if the BRP gave you white knuckles, take I-40. I-40 to US-411 at Newport TN. Then thru Sevierville and Pigeon Forge and US-321 to Townsend and TN-73 into the park.
My thoughts exactly. If you didn't enjoy BRP, they you wouldn't even enjoy the stretch from Sugarlands Visitor Center to the junction with 73 near Townsend. Good news is though that you shouldn't have a problem going into Cades Cove.
Best fuel prices on the route is the Walmart at Newport. Over in Townsend, there is fuel at descent price at IGA a couple miles to the right from where 321 turns in Townsend.
You have already been advised against Rt 129. I enjoy it and the shocked looks from the photographers stationed along the road, but I don't have a trailer.
Furthermore, don't take Foothills Parkway off of I-40 if you do decide to go through Gatlinburg. Instead go up one more exit to Hwy 321. Foothills Parkway goes up and over a mountain, definitely not enjoyable for you.
2015 Ram 3500 4x4 Crew Cab SRW 6.4 Hemi LB 3.73 (12.4 hand calc avg mpg after 92,000 miles with camper)
2004 Lance 815 (prev: 2004 FW 35'; 1994 TT 30'; Tents)