It'll take a LOT more than a bumpy road to break a carbon fiber fork. They're NOT fragile. Actually, carbon fiber forks have a reputation for being less jarring, transmitting less road shock, so many people prefer them for bumpy roads. Anyway, short of a major collision or getting something substantial caught up in your spokes -- the same things that would cause failure for a steel fork -- you're not likely to ever break one.

Your dented fork, on the other hand... It's probably safe to ride. FBinNY is about as trustworthy a source as there is, but there are some times when I'm personally inclined to err on the side of caution. A broken fork is among the worst possible failures on a bike. Lose your fork and you'll likely land on your face.

<EDIT> Also, since you mentioned aging of carbon fiber... UV exposure isn't always kind to the resins used to make carbon fiber components, but that's why carbon fiber components are finished with paint or UV-resistant coatings. I don't know if I'd ride a 100-year-old carbon fiber fork, but I'm confident the two carbon fiber forks I have on bikes will last a few more decades until I'm no longer able to ride. Well, unless I crash them, of course.