Never ever keep your money on exchanges!  This is how people lose control of their money!  An exchange can be hacked or scammed. You will lose everything then.  Keep your money on the wallet.

I think that it is necessary and necessary to keep all your funds in different purses, but of course if you have a lot of money. If you have $ 1000, it's probably worth keeping on your wallet, but it's not worth it to do on the stock exchange

Would it affect your life in any significant way if you woke up tomorrow and the coins were gone? If yes, just purchase a hardware wallet and store everything there. I'm not too worried with only ~$400 invested right now but as I pile in more mining income I'll be moving everything off the exchanges.

If you actively trade with your coins then you should keep them in exchange as it would save you all the fuss about transferring it from your wallet to exchange and vice versa but if you want to just invest in a coin and keep it for long term then you should use wallet as wallets are safer than exchange because exchanges get hacked many a times.

The direct purpose of any exchange is the conversion of one coin into another. If you keep coins on the exchange then you use it for other purposes - trading, pump&dump, etc... But this is not the main problem. The main thing is that the storage of coins on exchanges is very dangerous, because at each exchange hacker attacks are committed. It's much more reliable to store coins in cold or hardware wallets.

Its depends on you, you are free to do whatever you want. I f you want to hold your coins choose some wallet to stored your coins, but if you really want to tread your coins special to those eth token definitely you better to choose exchange, because if are going to stored your coins in exchange and you want to hold it you need to take the risk, its because is very risky like some people said, so be careful to your money because now a days there are a lot of hackers and scammers.

Good luck to your journey here in the crypto world.

To save your fund you should always put them in a wallet. Exchanges are only for trading. Do your trades then send directly to wallet.

If you wanna to hold for long term  my advice is to keep private keys somewhere safe. Keeping your holdings in exchange can be big threat against your expectations regarding selling them for profit after some time

I keep a minimum of coins on an exchange that I use for trading.
Because an Exchange could go offline or could be hacked.
It is always a risk!