It is not. They do wire money back into your account. In fact, if you're a US person, then you are covered by FDIC rules. During the hack, Bitfinex didn't touch money that was in USD; for the rest there was a haircut.
USD or US citizen? I'm pretty sure my USD got a haircut.
You can cash out using btc, xmr, eur,hkd, no problem. USD is the only unusable currency.
You specifically cannot cash out with HKD. The only ActualMoney you can get out of Bitfinex at present is Taiwan NTD to a local account.