I keep down items hanging so they don't compress. My tarp is always wiped down and dry then skinned in mesh snakeskins inside my pack in a gear closet. No problems w/it like this so far.
I think the key to keeping gear useful over years of use is keeping it clean and stored properly which to me means keeping down items out and expandable and everything else just clean and stored in protected places from elements/bugs.
This is my signature.