...a single event 50 foot displacement... I'm talking whole continents here; hundreds, maybe thousands of feet at a whack. For example, Darwin was astonished at the specter of the west coast of South America. You're familiar with his observations?
Sharp peaks and ridges? Think freeze/thaw cycle for instance, and its likely effect on, say, the Andes. If they've been there a gazillion years, WHY are they still sharp? If you've got some answers, I'll be happy to have a looksee.
If you have examples of what you speak, I'd be interested to hear them. You have to remember that prior to his SA trip, the largest mountains Darwin had ever encountered were in Scotland - a far cry from the cordillera described by Darwin. As far as the Andes are concerned, orogeny is an ongoing process, and few places are more dynamic than along the Chilean Trench. Why are they still sharp? Why wouldn't they be?