On the PCT, every time Yogi's book or the Schaffer guides or another hiker mentioned some perilous section upcoming, my friends and I would all yell in mock horror, "oh no, we're all going to die!" Well, none of us did. In fact, almost all of the trails reported dangers proved to be completely overblown:
Fuller Ridge--we got completely lost and ended up bushwacking straight down the mountain, but we got through. The snow was only an issue because we lost the trail.
The desert--no problem if you watch your water and don't hike during the heat of the afternoon.
Snow in the Sierras--annoying and difficult but far from impossible.
The closure in Glacier Peak--no problem, really.
The bottom line is that there are no insurmountable obstacles on the PCT. Hundreds of people thru-hike every year. Children have done it. Senior citizens have done it. I only wish the guidebooks would be a little bit better about stoking people's fears. It's all doable.