I added some btc to Bitfinex but then I heard that it was hacked recently.
Is this exchange still trusted? What are your thoughts?
Getting hacked is totally different from scamming members. I read after that hack they slowly paid all the withdraw requests. So, they did not get affected due to that hack. So, bitfinex is still a trusted services imho.
But the best practice would be just withdrawing your capital immediately after completing your trades with them. Do not use them as your online wallet. You will be safer.