Just yesterday, I deposited money from my bank account to Coinbase via SEPA. Refreshed the Coinbase page, and it was there, ready to buy digital currency with - so, the transaction was instant, or almost so. The transfer didn’t cost me anything, and neither did it Coinbase (it seems). Coinbase seems to be positive the transaction will settle, or else it wouldn’t let me use the money immediately, right? Reversibility…
It goes in the "direct debt" way as described, so your electricity or broadband supplier can charge you every month automatically
But you can also "push" a payment to someone else (or yourself, of course)
Not sure about fraud, from what I know, everyone that does a direct debt has an identifier that can be revoked in case of fraud. So it can happen, but there are ways to block fraudulent chargers.