There are many ways to store your bitcoins, I think it is a bad thing if you store your assets on exchangers
You can store your bicoin in the app blockchains which I think is quite safe
if you need money quickly, there are many exchangers that can use perfectmoney and there are still many withdrawal options
so you don't need to worry
Well, storing them in exchanges can really be quite dangerous but some people does not have enough gas to keep those Cryptocurrencies move from one place to another. Its actually better for day-traders to set specific time frames on when to trade and on when to make sure to keep their moneys in check so they can transfer it back to their safe wallets. I actually just do not see why some people risk the fact of leaving their money in other people's wallet.