No, no and no. You should never, ever, ever trust exchanges. At one point of time, exchanges would definitely screw up somewhere and you will never ever get your money back if you had money stored in that exchange.
You should never trust exchanges, sure. Any one of them can go belly up. But using them for trading and cashing in/out of the ecosystem is necessary. We also depend on exchanges for price discovery. Using them is a matter of risk management: Deposit, trade, then withdraw coins. Don't use them for storing funds. And I only store USD (while waiting to buy) on licensed exchanges that offer FDIC insurance for lost funds, like GDAX.
Etherdelta is the worst exchange ever. The UI is so shit you can't even use it properly.
Etherdelta is fine (assuming you use something like Metamask). Maybe it's not intuitive for novice traders, but I've never had any problems except thin order books.
