For actual touring , planning for a tour initially, using trip journals and the like, at least gives you an overview of how an area is. I personally don't see it as realistic to do Google street view everywhere, too much time, so actual tourers accounts help a lot.
But yes, there are times you just have to grit your teeth, use your mirrors wisely, and sometimes just take a minute and go off to the side of the road and let big bunches of cars trucks past, no big deal and with a good mirror and common sense, it works and not stressful.
Also, your mileage may vary. To one person it's all fine and to another they think it's the end of the world.
Being able to hold a line very well, and being confident in your bike handling skills are all crucial and helpful skills that go a long way to properly assessing danger and being ok with a given situation.