You can deposit and withdraw on your wallet page. Deposits and withdrawals are processed quickly. For small transfers this will be instant; for larger withdrawals it could take up to a couple hours.
There are no fees on deposits or withdrawals.
You can send USD Tether (USDT) to either an ERC20 address or an OMNI address. Just click withdraw and enter the address; FTX will automatically detect which you're using.
If you deposit funds to the wrong address, FTX is not responsible for any losses. If the funds are recoverable--e.g. sending an ERC20 token to your ETH address or OMNI USDT to your BTC address--we can try to recover the funds. Doing so is not guaranteed and might take up to a week. We also charge a $100 fee for recovery. Similarly, sending ETH via a smart contract to FTX may not be automatically credited, and may take time to recover.