I read something a while back in which a noted physicist bemoaned the fact that people just didn’t understand that it was utterly impossible to create a spaceship that could fly in the manner reported by UFO aficionados. The energy to pull this off simply cannot be harnessed in a vessel that is 100 feet wide. It’s not a matter of “we don’t know how, but they do.” It’s a matter of how energy fundamentally works.
Anyway, I fear you’re in the same boat. There’s no shoe that will do what you ask. Can’t be. Never will be. You want to put on a fairly heavy load, travel fast over rocky terrain, and somehow avoid pounding the soles of your feet, all while wearing glorified running shoes. Now, I admit people can and do get away with trail runners while backpacking. But in most cases that’s with lighter loads, and in all cases it’s on smoother trails.
A running shoe, even a trail runner, needs to be light and flexible, yet have decent cushioning. To do this, these shoes have light midsoles made of polyurethane or EVA foam, while backpacking boots use stiff nylon or even steel. Trail runners also have thinner outsoles, with ridges cut across them for flex. Backpacking soles have thick lugs and relatively little flex. Bottom line: The thinness and light weight of the materials in a trail runner simply makes it impossible to armor your feet in the way a backpacking boot does. That’s why they MAKE backpacking boots, to protect your feet in the conditions you describe.
Anyway, maybe you could try a lightweight hiker like the Asolo FSN 70 GTX ($140). Quite light (two pounds, six ounces) even when compared to the Montrail Vitesses (one pound, eight ounces). Good protection for your feet, yet flexible and comfortable. Or, just add more cushioning to your trail runners by adding an insole such as Superfeet ($28). They add stability, cushioning, and an extra layer of protection.