actually it's safe if trading in etherdelta, as long as my transaction in etherdelta I have no problem and safe. but sometimes even think that until the privat key we are known to the same person who is not responsible then it can be hacked on our wallet
i agree on it mate because i do also trade in ed and so far i dont experience any problem in regards to their service but i am aware that ed has a lot of phishing sites which could lead to some seriuos problems to you if you are not careful enough about your transactions .
that is why it is also recomended to bookmark the original site of ed in order to avoid getting phished or else you can you use any other extension such as metamask or use any other methods to unluck your ed wallet excrpt from private keys .