Once we do get decentralised exchange this should become less of a risk.
As you mention Bitshares exchange already does this although not many people I know use it. The success of STEEM and Steemit may persuade people to take a second look. Personally I'm not a fan of the interface vs somewhere like Poloniex. I had to use it to trade a token I was invested in and just found it difficult to use. That can easily be improved though.
WAVES is also supposed to be creating a decentralised exchange (amongst their other goals) if they can ever get it off the ground I think that could be massive. It was one of the main reasons I got onboard with it early. The potential is huge if they succeed.
Someone in another post suggested that the Bitfinex hack may in part have occurred due to them changing the way they keep customer funds as a result of the US financial regulators fining them (I think last year). I don't know enough about it to be sure.
I would bet anyone a Coke though that this will turn out to be another inside job. Seems par for the course for these hacks.
Also they seem to be happening almost like clockwork whenever markets are on a boom - in this case it seemed to coincide with the ETC surge (may just be coincidental).
I agree that BitShares Exchange's interface could be improved. Feel free to tell the developers what to improve, ideally in https://github.com/cryptonomex/graphene-ui/issues
To be honest if they could just replicate what Poloniex do I would be happy. That is IMO the best interface for ease of use. I don't think these kinds of layouts/interfaces are patented are they?