Digital documents, even after encrypted....can be decrypted.
No,if they're further secured with Digital Signatures,mostly no-access to a stranger would be granted.BruteForcing or Decrypting the hashes would take ages.
key and then posted it on cloud storage. This is stupid, because most online activities are logged and monitored.
That is the most convenient way a hacker can gain access to private stuff.
You print the paper wallet, and then laminate it, to keep it dry. Most digital media fail after a few years... so I hope you burnt some copies onto some CD's or DVD's
And make sure you keep it safe from a place full of rats ? Because they might shred paper into pieces.
CD's could re-written,their password access can be easily broken.