Coinspot is good to buy/sell as its Australian. There is an intensive verification process.
They have wallets set up that allow for 2 factor authentication which is good.
To be safe if you are going to buy alot of these coins and have exposure to get yourself an offline wallet (i.e. nano S or something similar). Then just transfer your coins onto there.
if you plan on trading, its ok to leave there... but the fees are expensive.
