only remark is waiting time for approval withdraw transaction. last time >15h
Poloniex is not safe and ok. Many transactions "disappear" and the support doesn't answer for months.
I sent a couple of ether to Poloniex, never arrived in account although in etherscan its a perfectly fine transaction to the correct address with more than thousand positive confirmations. Poloniex doesn't let me access my own funds.
Talked about that on twitter, many people DM'd me with the same issue. Actually, it is just a matter of time until they also take money from you without any reason. Good luck
I have deposits that go MIA as well.
You need to open up a support ticket with them and they fix it fairly fast.