This is actually something that I was thinking about before I found Dual Universe. The idea of coming across a previous player's work, falling apart from age and neglect and learning the story of what happened is really interesting to me.
I like your idea on countering decay and the gameplay aspects that could be added from decay and dealing with it. The issue is demonstrating decay. It could just make random holes in your ship as it gets old or it could slowly damage elements (thusters, guns, cockpits, etc.) somewhat like Space Engineers, where blocks take time to build, and subsequently destroy until they don't work but are still physically present.
If that could be figured out, I think it would be a great feature to add further along in the development, say after the game has been released, because (not that I'm a developer) I think it would probably take some time to implement and balance.
Also this topic was discussed a couple months ago if you want to read through it HERE