i just saw the same in a documentary about biking in germany. major roads in rural areas have absolutely no space for bikes. cars go at the speed limit, and riding a bike from one village to the next is more dangerous than any city.
It's certainly not as bleak as you describe.
as for alternative roads, that really depends. generally from my experience between two neighboring villages there tends to be only one road, unless you want to make a big detour. sometimes alternate roads exist when and old main road is replaced with a new one on a different route.