I’m sorry but nobody here can predict if your case encounters any issues down the line that might require some digging in any old documents you have submitted. In my opinion, immigration can be unpredictable. I also do not know what kind of documents you have, if you have a lot of ‘fluff’ that people submit such as endless pages of chats, then I would purge those. If that answer does not satisfy you, then by all means you can do what makes you comfortable, i.e. shredding everything.