They may wash out a little more, but are more forgiving at the same time. If o=you are going massive, some camber might help. Id go medium flex for some bigger stuff
If you land well, no problem at all, in fact I tend to find softer skis (im talking wider and softer, not a thin soft park ski) more stable and much more enjoyable to stomp when you land well.
If you land on your tails, yeah you'll end up on your ass more than on stiffer skis, but imo it's almost better, landing on your tails on stiff skis kills your shins/calves.
So yeah, if you're not comp skiing on an icy slope, you'll be just fine