"but are they going to snap off at the ends if they're banged against a rock?"
Not in my experience. I used them last year on the Teton Crest trip, and banged them against plenty of rocks. They'll break, of course, if you get them wedged between rocks and you keep on going.
I, and others, use a very light grip on the poles. If they wedge, they come out of my hand. No snapping. I've had my pair for a couple of years with no issues.