Paper wallets are great but then you run the risk of losing it all in a fire.
Storing photocopies in more than one geographic location mitigates that risk significantly.
An alternative digital solution is to store all your seeds in a single text file encrypted and uploaded to multiple online locations. That way you just have to remember one password to ...
It clearly says this in the Terms and conditions page.
"Accounts which are inactive for longer than 365 days may be deleted. Any remaining balance will be treated as a donation to the Pool."
So yes you can loose your mined coins by being inactive for long.