4. Etherdelta! You should avoid it because its really complex to use and you can easily make a mistake.
Then let's educate people how to use it, rather than telling them to avoid it. Avoid it why? Because it is hard to use, are you out of your mind? Etherdelta is one of the safest exchanges I ever used, yes it is only for ethereum-erc20 tokens but as decentralized exchange it is surley place where we as people will want to move towards.
3. IDEX, not sure if this falls in the exchange category but this thing is fking slow. You can't withdrawal your tokens without having $50 worth of Eth.
For IDEX, yes it's shity they have this limit, but many exchanges out there have it such as Binance, it is slow cuz you gotta wait the blocks to come in.