The theory is that you seldom bring back a Storm Shadow, because the CONOPS is such that you don't take off with it unless you are going to use it. It's not like you're going to loiter around waiting for a bunker 200 miles away to pop up.
FiberMat - This is much misunderstood.
AFAIK it replaces part of the stealth surface treatment - a conductive layer that deals with surface currents, which can otherwise cause scattering in undesirable directions. There are still spray-on coatings, aperture edge treatments and (most likely) RAS edges on the wings and empennage.
The other innovation is a RAM that has the same kind of base as helicopter blade anti-erosion coatings. That's the stuff (I believe) that is supposed to be damage-resistant and damage-tolerant.