I suggested the OP pose this question here for the great feedback, as we’ve not driven the island in awhile. But I agree that it is not really intimidating if you keep to certain roads. We’ve driven over the hill from Road Town to CG and are fine with that. But for friends planning to visit who prefer the less steep roads - where possible - I told them there are alternative routes when driving between the north and south areas of the island. For example, from the airport or Road Town to CGB they can drive along the south shore (Sir Francis Drake if I recall), and take the Zion Hill Rd over to the north shore road. Then up over Windy Hill Rd past Heritage Inn and down into CGB. It’s mostly flat with nicer views to boot.
And yes it is a good idea to blow the horn before taking corners (for goats) and switchbacks (for oncoming traffic)…

Tortola is a gorgeous island to use as a base and worth getting accustomed to the driving…