I want to earn interest on my coins (BTC,ETH,LTC) therefore I prefer to leave these in Exchange for funding purpose, however I have No plan to sell or exchange with other coin in near future.
I always keep my withdrawal blocked by changing password every 5th day.
Is it 100% safe to keep crypto's in exchange like Bitfinex or others with withdrawal locked ?
It is not safe at all to keep your crypto in exchanges. No matter how many times you change your password, you are not in charge of your private keys. Your account could be hacked even with your password. Put your funds where you have absolute control. Hardwallet etc