I added some btc to Bitfinex but then I heard that it was hacked recently.
Is this exchange still trusted? What are your thoughts?
Well if you are doubt on bitfinex because of hacking issue, more better don't use their service and personality i am believe on them because they have fixed the bugs on their service.
somehow i am agree with densuj said and there is many good exchangers you can trade with like kraken, bitstamp, btc-e or else, but i think kraken is a good option for you. as long as you don't use all of your bitcoin in one exchanger then you are fine to go with trading, so you can trade with many exchanges.